SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                    ________

                                    FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER
                      PURSUANT TO RULE 13A-16 OR 15D-16 OF
                       THE SECURITIES EXCHANGE ACT OF 1934

                         For the month of February, 2004

                                   Serono S.A.
                    ----------------------------------------
                               (Registrant's Name)

                            15 bis, Chemin des Mines
                                 Case Postale 54
                                CH-1211 Geneva 20
                                   Switzerland
                    ----------------------------------------
                    (Address of Principal Executive Offices)

                                     1-15096
                    ----------------------------------------
                              (Commission File No.)

     (Indicate by check mark whether the registrant files or will file annual
reports under cover of Form 20-F or Form 40-F.)

     Form 20-F  X    Form 40-F
               ---             ---

     (Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101 (b)(1).) ___

     (Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101 (b)(7).) ___

     (Indicate by check mark whether the registrant by furnishing the
information contained in this form is also thereby furnishing the information to
the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of
1934.)

     Yes       No  X
         ---      ---

     (If "Yes" is marked, indicate below the file number assigned to the
registrant in connection with Rule 12g3-2(b): 82-______)



                                                                          SERONO


MEDIA RELEASE

FOR RELEASE FEBRUARY 2, 2004, 4:01 PM EST
-----------------------------------------


--------------------------------------------------------------------------------
             RECORD YEAR FOR SERONO WITH OVER $2 BILLION IN REVENUES

                - Net income up 21.6% to $390.0 million in 2003 -
--------------------------------------------------------------------------------


ROCKLAND,  MA,  FEBRUARY  2, 2004 - 04:01 PM EST - Serono (virt-x: SEO and NYSE:
SRA),  the  third largest biotechnology company in the world, today reported its
fourth  quarter  and  full  year results for the period ended December 31, 2003.


KEY  POINTS  FOR  FULL  YEAR  2003

     -    Total  revenues  up  31.3% to $2,018.6m (up 20.9% in local currencies)

     -    Neurology now Serono's largest therapeutic area with sales up 54.9% to
          $850.2m

     -    Reproductive  Health  core  portfolio  growing  at  20.7%  to  $593.7m

     -    Reported net income up 21.6% to $390.0m (up 14.2% in local currencies)
          and  up  26.9%  (or 18.9% in local currencies) excluding non-recurring
          non-operational  charges

     -    Reported  EPS  up  22.7%  to $24.63 per bearer share and $0.62 per ADS

     -    Proposed  dividend  of  CHF8.0 per bearer share and of CHF0.2 per ADS*

     -    2004  growth  outlook  in  local  currencies  of 12% or more for total
          revenues  and  15%  to  20%  for  net  income


"2003  was  a record year for Serono with total revenues breaking through the $2
billion  mark,"  said  Ernesto  Bertarelli,  Chief  Executive Officer of Serono.
"Going  forward  we  are  very  well  positioned  to  take advantage of the many
opportunities  which  exist  in  the  biotech  sector."

 "We  forecast  another  strong financial performance in 2004," said Allan Shaw,
Chief  Financial  Officer.  "This  year,  we  expect our net income growth to be
between  15%  and  20%,  inclusive  of  launch  costs  for  Raptiva(TM)."


                                     -more-

FOURTH  QUARTER  AND  FULL  YEAR  FINANCIAL  PERFORMANCE

Total  revenues  increased  by  31.3%  to $2,018.6m in the full year 2003 (2002:
$1,537.8m),  and  by  29.1%  to  $565.1m  in the fourth quarter (2002: $437.7m).

Worldwide  product sales were $1,858.0m in 2003, up 30.6% (2002: $1,423.1m), and
up  26.8%  to  $519.3m  in  the fourth quarter (2002: $409.4m).  Notwithstanding
weakness  in  the  US dollar, product sales in local currencies grew by 19.9% in
2003  and  16.5%  in  the  fourth  quarter.

Royalty  and  licensing  income  increased  by  40.0%  to $160.6m in 2003 (2002:
$114.7m),  and  was  up  61.8%  to  $45.8m (2002: $28.3m) in the fourth quarter,
reflecting  the  company's  strong  intellectual  property  rights.

Gross  margin  increased  to  85.0% of product sales in 2003 (2002: 84.3%), as a
result  of  continuing  manufacturing  improvements leading to higher production
yields.  In  the  fourth  quarter  of 2003 gross margin was 84.5% (2002: 84.1%).

Selling,  General  and  Administrative  expenses  were $636.8m or 31.5% of total
revenues  in  2003  (2002:  $504.2m  or  32.8%  of total revenues), and 31.7% of
revenues  at $178.9m in the fourth quarter (2002: $144.5m or 33.0% of revenues).
The  decrease in SG&A as a percentage of revenues reflects an improvement in the
company's  operating  leverage  in  2003.

Research and Development expenses were $467.8m or 23.2% of total revenues (2002:
$358.1m  or  23.3% of total revenues) for the full year, and $124.2m or 22.0% of
total  revenues in the fourth quarter (2002: $95.4m or 21.8% of total revenues).

Other  operating expenses in 2003 were $199.5m (2002: $85.8m), and $49.2m (2002:
$27.7m)  in  the  fourth  quarter.  The  increase  in  other  operating expenses
reflects  payments  related  to licensing agreements for new products and higher
royalties  paid  to  third  parties.

Full  year 2003 operating income increased by 24.4% to $434.9m or 21.5% of total
revenues (2002: $349.6m or 22.7% of total revenues), and was up 49.5% to $132.4m
in the fourth quarter or 23.4% of total revenues (2002: $88.6m or 20.2% of total
revenues).

Net  financial income was $44.0m in 2003 (2002: $36.5m) and $15.2m in the fourth
quarter  (2002:  $9.2m).

Other  expense was $19.7m in 2003 (2002: $1.7m) and $16.1m in the fourth quarter
(2002:  income  of $0.2m), reflecting non-recurring non-operational charges.  In
the  fourth quarter, the company took a non-cash charge of $16.1m related to the
write-down  of  an  equity  investment  made  in  Swiss International Air Lines.


                                     -more-

Total  taxes  in  2003 were $68.9m, representing an overall tax rate of 15.0% of
profit  before tax (2002: $63.1m, or 16.4% of profit before tax).  In the fourth
quarter, taxes were $19.7m, or 15.0% of profit before tax (2002: $15.8m or 16.2%
of  profit  before  tax).

Reported  net  income  in  the  full  year  2003  was up 21.6% to $390.0m (2002:
$320.8m), or 14.2% in local currencies.  Excluding non-recurring non-operational
charges,  net income growth was 26.9%, or 18.9% in local currencies in 2003.  In
the  fourth  quarter,  reported  net  income  grew  36.8%,  or  25.8%  in  local
currencies,  to  $111.6m  (2002:  $81.6m).

Basic  earnings  per share (EPS) were up 22.7% to $24.63 per bearer share (2002:
$20.07)  and  $0.62  per  American  Depositary  Share  (ADS)  (2002:  $0.50).

On  May  25,  2004,  the  Board  of Directors will propose to the Annual General
Meeting  a cash dividend of CHF8.0 per bearer share, CHF3.2 per registered share
or  CHF0.2  per  ADS*, representing an increase of 14.3% over the 2002 dividend.

For  the  full  year  ended  2003,  net  cash flow from operating activities was
$542.9m  (2002:  $532.0).  When  excluding one-time payments received from third
parties  in  connection  with the signing of collaborative agreements (Pfizer in
2002  and  OSI  Pharmaceuticals  in  2003), operating cash flows increased 47.0%
compared  to  2002.

As of December 31, 2003, there were 15.812 million outstanding equivalent bearer
shares  of  Serono  SA.

NEUROLOGY

Neurology  sales  were  up  54.9%  to $850.2m for the full year 2003, and fourth
quarter sales were $242.2m.  Full year sales of Rebif(R) were up 49.3% (34.1% in
local  currencies) to $819.4m (2002: $548.8m).  In the fourth quarter, worldwide
sales  of  Rebif(R)  increased  by  35.9% (22.7% in local currencies) to $233.2m
(2002:  $171.5m).

Sales of Rebif(R) in the US were up 60.0% to $55.7m in the fourth quarter (2002:
$34.8m). In 2003, with $188.5m sales for the full year, representing an increase
of  164.8%  (2002:  $71.2m),  Rebif(R)  was clearly the fastest growing multiple
sclerosis (MS) therapy in the US, more than doubling its market share during the
year.

Rebif(R)  continues  its  market  leadership  outside  the  US  with  2003 sales
increasing  by  32.1%  to  $630.8m  (2002: $477.6m). European sales increased by
39.0%  (16.9% in local currencies) to $436.8m (2002: $314.1m). Sales outside the
US  were  $177.5m  in  the  fourth  quarter  (2002:  $136.7m).


                                     -more-

In 2003, the performance of Rebif(R) was supported by the release of a series of
positive study results. These included the final 63-week EVIDENCE study results,
data  showing  greater  efficacy  with  Rebif(R)  in patients who converted from
Avonex(R)  to Rebif(R) at the end of the comparative phase of the study, as well
as  the  safety  and efficacy results from the eight-year long-term follow-up of
the  PRISMS  study.

Given  the  strong  performance  of Rebif(R) in 2003, the company is on track to
achieving  its  goal  of  worldwide  market  leadership  by  the  end  of  2006.

Novantrone(R)  sales  in  MS  were  $30.9m  in 2003 and $9.0m the fourth quarter
(total  Novantrone(R)  sales were $77.1m in 2003 and $22.4m the fourth quarter).

REPRODUCTIVE  HEALTH

In  2003,  worldwide  reproductive  health  sales  grew  11.4% to $692.9m (2002:
$621.9m),  and by 15.2% to $191.0m in the fourth quarter (2002: $165.8m).  Sales
of  Gonal-f(R)  increased  by 16.8% (7.3% in local currencies) to $526.1m (2002:
$450.4m)  in  the full year, and by 21.6% (11.2% in local currencies) to $147.5m
(2002:  $121.3m)  in  the  fourth  quarter.

Serono's  core  reproductive  health  portfolio  consisting of three recombinant
hormones (Gonal-f(R), Ovidrel(R)/Ovitrelle(R), Luveris(R)) and two complementary
products (Cetrotide(R), Crinone(R)) grew by 20.7% (10.7% in local currencies) to
$593.7m  representing  85.7%  of total reproductive health sales in 2003. In the
fourth  quarter this core portfolio grew by 25.6% (14.7% in local currencies) to
$168.1m  (2002:  $133.8m).

In  October, the Ovidrel(R)/Ovitrelle(R) pre-filled syringe was approved by both
the  FDA  and  the  European Commission making it the first liquid, ready-to-use
recombinant  hCG..

METABOLIC  ENDOCRINOLOGY

Saizen(R) sales increased by 22.1% (11.0% in local currencies) to $151.5m (2002:
$124.0m)  in 2003, and were up 17.4% (7.1% in local currencies) to $42.3m (2002:
$36.0m)  during  the  fourth  quarter.

Serostim(R)  sales  were  $88.8m  for  the  full year (2002: $95.1m), and $22.8m
(2002:  $26.5m)  in  the  fourth  quarter.

In  December  2003,  the FDA approved Zorbtive(TM) [somatropin (rDNA origin) for
injection],  Serono's recombinant human growth hormone, for use in the treatment
of  short  bowel syndrome, a serious and potentially life-threatening condition.
Zorbtive(TM) was granted orphan drug status for use in the treatment of patients
with  short  bowel  syndrome  by  the FDA Office of Orphan Products Development.


                                     -more-

PSORIASIS

Serono  is  committed  to developing and commercializing new biotherapeutics for
psoriasis,  a  chronic  skin  disease.
On  October 27, 2003, our partners Genentech and XOMA announced that Raptiva(TM)
(efalizumab)  was  approved  by  the  FDA  for  the  treatment  of  chronic
moderate-to-severe  plaque psoriasis.  Raptiva(TM) is the first biologic therapy
designed  to  provide  continuous  control  of chronic moderate-to-severe plaque
psoriasis  and  can  be  self-administered by patients as a single, once-weekly,
subcutaneous  injection.  Long-term  data  on  Raptiva(TM)  was presented at the
American  Academy  of  Dermatology  in  July  2003.

Serono  is  responsible for developing and commercializing Raptiva(TM) worldwide
outside  of  the  United  States  and  Japan.  During  2003,  Serono  submitted
regulatory  applications  in  key  markets  for  the  use  of  Raptiva(TM)  in
moderate-to-severe plaque psoriasis and currently expects to commence its launch
program  for  this  innovative  therapy  in  the  second  half  of  2004.  Costs
associated  with  the launch of Raptiva(TM) are projected to be between $30m and
$50m  in  2004.

REGIONAL  SALES

North American sales grew by 44.8% to $694.3m in 2003 (2002: $479.6m).  European
sales  increased by 31.2% to $813.8m (2002: $620.4m).  In the rest of the world,
sales  grew  by  8.3%  to $349.9m (2002: $323.2m).  In the fourth quarter, North
American  sales were up 32.2% to $192.7m (Q4 2002: $145.8m) while European sales
grew  by  31.0% to $233.0m (Q4 2002: $177.8m) and sales in the rest of the world
increased  by  9.1%  to  $93.6m  (Q4  2002:  $85.8m).

R&D  NEWS

A  multicentre  multinational  head-to-head  trial  comparing  Rebif(R)  vs.
Copaxone(R)  was  recently  initiated.  This  is  a  2-year  study  with  a
relapse-related  primary  endpoint,  as well as other clinical and MRI secondary
endpoints.

During  the  last  twelve  months,  key  R&D  highlights  were:

     -    In June, positive Phase 2 results for onercept (r-hTBP-1) in psoriasis
          were presented at the 9th International Psoriasis Symposium. A Phase 3
          program  is  scheduled  to start in due course following completion of
          discussions  with  the  FDA.

     -    Phase 2a studies with IL-18 binding protein were started in rheumatoid
          arthritis  and  psoriasis.

     -    A  Phase  2  trial  with  anastrozole  for  follicular development and
          ovulation  induction in infertile women with ovulatory dysfunction was
          initiated  in  the  first  quarter.  The  study outcome is expected by
          mid-2004.

     -    In  June, positive results from a proof of concept study of emfilermin
          (r-hLIF)  for  improving  embryo  implantation in women with recurrent
          implantation


                                     -more-

          failure  were  presented  at  ESHRE. A Phase 2 study aiming to enhance
          embryo  implantation  in  patients  who have a history of previous IVF
          failures  was initiated during the second quarter. The outcome of this
          study  is  anticipated  in  the  second  half  of  2004.

During  the  last  twelve  months,  significant  regulatory milestones were also
achieved  including:

     -    Positive European CPMP opinion for Gonal-f(R) pre-filled pen injector,

     -    Favorable FDA advisory committee recommendation for Luveris(R) in
          treatment  of  profoundly  LH-deficient  women,

     -    EMEA  and  FDA approvals of Ovidrel(R)/Ovitrelle(R) pre-filled syringe
          for  infertility,

     -    FDA approval of Zorbtive(TM) for use in patients with short bowel
          syndrome.


CONFERENCE  CALL  AND  WEBCAST

Serono  will  hold a conference call on February 3rd, 2004, starting at 11:00 am
Eastern Time (5:00 pm Central European Time) during which Serono Management will
present  the  Company's  Fourth  Quarter and Full Year 2003 Results. To join the
telephone  conference please dial 412 858 4600 (from the US), 091 610 5600 (from
Switzerland),  0207 866 4111 (from the UK) and +41 91 610 5600 (from elsewhere).
Telephone  playback  will  be  available  one hour after the conference call and
until  close  of  business  5.00  pm  ET  on February 6th, 2004.  To access this
playback  please dial the following numbers: 412 858 1440 (from the US), 091 612
4330  (from  Switzerland), 0207 866 4300 (from the UK) and +41 91 612 4330 (from
elsewhere)  and  enter  the  PIN  code  247#  from  a  touch  tone  telephone.

The  event  will  also be relayed by live audio webcast which interested parties
may  access  via  Serono's  Corporate  home  page, www.serono.com. A link to the
webcast  will  be  provided  immediately  prior to the event.  Additionally, the
webcast  will  be available for replay until close of business on February 20th,
2004.


                                     -more-

                                       ###
Some  of  the  statements  in  this  press  release  are  forward  looking. Such
statements  are inherently subject to known and unknown risks, uncertainties and
other  factors  that  may  cause  actual results, performance or achievements of
Serono  and  affiliates  to  be  materially  different  from  those  expected or
anticipated  in  the  forward-looking statements. Forward-looking statements are
based on Serono's current expectations and assumptions, which may be affected by
a  number  of  factors, including those discussed in this press release and more
fully  described  in  Serono's  Annual  Report  on Form 20-F filed with the U.S.
Securities and Exchange Commission on April 17, 2003.  These factors include any
failure  or  delay  in  Serono's ability to develop new products, any failure to
receive  anticipated  regulatory  approvals,  any  problems  in  commercializing
current  products  as  a  result of competition or other factors, our ability to
obtain  reimbursement  coverage  for  our  products,  and government regulations
limiting  our  ability  to  sell  our  products. Serono has no responsibility to
update the forward-looking statements contained in this press release to reflect
events  or  circumstances  occurring  after  the  date  of  this  press release.
                                       ###

ABOUT SERONO
Serono  is  a  global  biotechnology  leader.  The Company has seven recombinant
products,  Rebif(R),  Gonal-F(R),  Luveris(R),  Ovidrel(R)/Ovitrelle(R),
Serostim(R), Saizen(R) and Zorbtive(TM) (Luveris(R) is not approved in the USA).
In  addition to being the world leader in reproductive health, Serono has strong
market  positions  in  neurology,  metabolism and growth. The Company's research
programs  are  focused  on  growing  these  businesses  and  on establishing new
therapeutic  areas.  Currently,  there  are approximately 30 ongoing development
projects.

In  2003,  Serono  achieved  worldwide revenues of US$2,018.6 million, and a net
income  of  US$390.0 million, making it the third largest biotech company in the
world.  Its products are sold in over 90 countries. Bearer shares of Serono, the
holding  company,  are  traded  on  the virt-x (SEO) and its American Depositary
Shares  are  traded  on  the  New  York  Stock  Exchange  (SRA).


*i.e.  $0.16  based on an exchange rate of $1=CHF1.2562, as of January 30, 2004.
The actual dividend will be based on the exchange rate in effect on the date the
dividend  is  converted  into  $  by  the  depositary  for  the  ADS.


FOR  MORE  INFORMATION,  PLEASE  CONTACT:

  SERONO IN GENEVA, SWITZERLAND:
  MEDIA RELATIONS:              INVESTOR RELATIONS:
  Tel:  +41-22-739 36 00        Tel:  +41-22-739 36 01
  Fax:  +41-22-739 30 85        Fax:  +41-22-739 30 22
  http://www.serono.com         Reuters: SEO.VX / SRA
  ---------------------         Bloomberg: SEO VX / SRA US


  SERONO, INC., ROCKLAND, MA
  MEDIA RELATIONS:              INVESTOR RELATIONS:
  Tel.   +1 781 681 2340        Tel.   +1 781 681 2552
  Fax:  +1 781 681 2935         Fax:  +1 781 681 2912
  http://www.seronousa.com
  ------------------------


On  the  following  pages,  there  are:
     -    Tables  detailing  sales  in  dollars  by therapeutic area, geographic
          region  and the top 10 products for the 3 and 12 months ended December
          31,  2003  and  2002.
     -    Consolidated  statements  of  income  for  the  3  and 12 months ended
          December  31, 2003 and 2002, the consolidated statements of cash flows
          for  the  12  months  ended December 31, 2003 and 2002, as well as the
          consolidated  balance  sheets and consolidated statements of equity as
          of December 31, 2003 and 2002. These consolidated financial statements
          have  been  prepared on the basis of International Financial Reporting
          Standards.  The  accompanying  notes  to  these consolidated financial
          statements  will be available upon the release of Serono's 2003 Annual
          Report.


                                     -more-



                            SALES BY THERAPEUTIC AREA
                            -------------------------

                            THREE MONTHS ENDED                    THREE MONTHS ENDED
                            DECEMBER  31, 2003                    DECEMBER  31, 2002
                                                             
                          $  MILLION  % OF SALES   % CHANGE $   $  MILLION  % OF SALES
---------------------------------------------------------------------------------------
Neurology                      242.2        46.6%        41.0%       171.8        42.0%
Reproductive Health            191.0        36.8%        15.2%       165.8        40.5%
Growth & Metabolism             65.1        12.5%         4.2%        62.5        15.3%
Others                          21.0         4.1%       123.4%         9.3         2.2%

---------------------------------------------------------------------------------------
Total sales(US$ million)  $    519.3         100%        26.8%  $    409.4         100%


                           SALES BY GEOGRAPHIC REGION
                           --------------------------

                            THREE MONTHS ENDED                    THREE MONTHS ENDED
                            DECEMBER  31, 2003                    DECEMBER  31, 2002

                          $  MILLION  % OF SALES   % CHANGE $   $  MILLION  % OF SALES
---------------------------------------------------------------------------------------
Europe                         233.0        44.9%        31.0%       177.8        43.4%
North America                  192.7        37.1%        32.2%       145.8        35.6%
Latin America                   29.4         5.7%        14.0%        25.8         6.3%
Others                          64.2        12.3%         7.0%        60.0        14.7%

---------------------------------------------------------------------------------------
Total sales(US $million)  $    519.3         100%        26.8%  $    409.4         100%


                            SALES BY THERAPEUTIC AREA
                            -------------------------

                            TWELVE MONTHS ENDED                  TWELVE MONTHS ENDED
                             DECEMBER 31, 2003                    DECEMBER 31, 2002

                          $  MILLION  % OF SALES   % CHANGE $   $  MILLION  % OF SALES
---------------------------------------------------------------------------------------
Neurology                      850.2        45.8%        54.9%       549.1        38.6%
Reproductive Health            692.9        37.3%        11.4%       621.9        43.7%
Growth & Metabolism            240.2        12.9%         9.6%       219.1        15.4%
Others                          74.7         4.0%       125.6%        33.0         2.3%

---------------------------------------------------------------------------------------
Total sales(US $million)  $  1,858.0         100%        30.6%  $  1,423.1         100%


                           SALES BY GEOGRAPHIC REGION
                           --------------------------

                            TWELVE MONTHS ENDED                  TWELVE MONTHS ENDED
                             DECEMBER 31, 2003                    DECEMBER 31, 2002

                          $  MILLION  % OF SALES   % CHANGE $   $  MILLION  % OF SALES
---------------------------------------------------------------------------------------
Europe                         813.8        43.8%        31.2%       620.4        43.6%
North America                  694.3        37.4%        44.8%       479.6        33.7%
Latin America                   98.8         5.3%       (9.5%)       109.2         7.7%
Others                         251.1        13.5%        17.3%       213.9        15.0%

---------------------------------------------------------------------------------------
Total sales(US $million)  $  1,858.0         100%        30.6%  $  1,423.1         100%



                                     -more-



                                    TOP TEN PRODUCTS
--------------------------------------------------------------------------------------


                            THREE MONTHS ENDED                   THREE MONTHS ENDED
                             DECEMBER 31, 2003                    DECEMBER 31, 2002
                           -----------------------------------------------------------

                   * TA      $MILLION  % OF SALES   % CHANGE $   $MILLION  % OF SALES
                                                         
Rebif(R)        MS              233.2        44.9%        35.9%     171.5        41.9%
Gonal-f(R)      RH              147.5        28.4%        21.6%     121.3        29.6%
Saizen(R)       Growth           42.3         8.1%        17.4%      36.0         8.8%
Serostim(R)     Wasting          22.8         4.4%      (13.9%)      26.5         6.5%
Novantrone(R)   MS/Oncology      22.4         4.3%      3372.7%       0.6         0.2%
Pergonal(R)     RH               11.9         2.3%      (10.6%)      13.3         3.2%
Cetrotide(R)    RH                7.7         1.5%        42.3%       5.4         1.3%
Crinone(R)      RH                6.4         1.2%       105.5%       3.1         0.8%
Metrodin HP(R)  RH                5.3         1.0%      (49.6%)      10.4         2.5%
Stilamin(R)     Other             3.9         0.7%         5.8%       3.7         0.9%


                            THREE MONTHS ENDED                   THREE MONTHS ENDED
                             DECEMBER 31, 2003                    DECEMBER 31, 2002
                           -----------------------------------------------------------

                       * TA  $MILLION  % OF SALES   % CHANGE $   $MILLION  % OF SALES

Rebif(R)        MS              819.4        44.1%        49.3%     548.8        38.6%
Gonal-f(R)      RH              526.1        28.3%        16.8%     450.4        31.7%
Saizen(R)       Growth          151.5         8.2%        22.1%     124.0         8.7%
Serostim(R)     Wasting          88.8         4.8%       (6.6%)      95.1         6.7%
Novantrone(R)   MS/Oncology      77.1         4.1%     11866.3%       0.6         0.0%
Pergonal(R)     RH               45.8         2.5%       (0.4%)      46.0         3.2%
Cetrotide(R)    RH               24.8         1.3%        35.3%      18.4         1.3%
Metrodin HP(R)  RH               24.8         1.3%      (50.6%)      50.1         3.5%
Crinone(R)      RH               20.8         1.1%        90.2%      10.9         0.8%
Profasi(R)      RH               15.4         0.8%      (22.4%)      19.8         1.4%


                                  * THERAPEUTIC AREAS
                RH     = Reproductive Health      Wasting  = AIDS Wasting
                MS     = Multiple Sclerosis       Growth   = Growth Retardation
             Oncology  = Oncology



                                     -more-



CONSOLIDATED INCOME STATEMENTS


THREE MONTHS ENDED DECEMBER 31                 2003 *       % OF                   2002 *       % of
                                              US$'000   REVENUES       % change   US$'000   Revenues
                                                                             

Revenues
Product sales                                 519,276                      26.8%  409,429
Royalty and license income                     45,788                      61.8%   28,307
-----------------------------------------------------------------------------------------------------
TOTAL REVENUES                                565,064          100.0%      29.1%  437,736      100.0%
-----------------------------------------------------------------------------------------------------
Operating Expenses
Cost of product sales                          80,418                      23.4%   65,167
% of Sales                                       15.5%                               15.9%
Selling, general and administrative           178,865           31.7%      23.8%  144,518       33.0%
Research and development                      124,208           22.0%      30.2%   95,418       21.8%
Restructuring                                       0            0.0%   (100.0%)   16,303        3.7%
Other operating expense, net                   49,156            8.7%      77.2%   27,748        6.3%
-----------------------------------------------------------------------------------------------------
Total Operating Expenses                      432,647           76.6%      23.9%  349,154       79.8%
-----------------------------------------------------------------------------------------------------
OPERATING INCOME                              132,417           23.4%      49.5%   88,582       20.2%
-----------------------------------------------------------------------------------------------------
Financial income, net                          15,154                      65.6%    9,152
Other (expense)/income, net                   (16,124)                 (9313.7%)      175
-----------------------------------------------------------------------------------------------------
Total Non Operating (Expense)/Income, Net        (970)                              9,327
-----------------------------------------------------------------------------------------------------
Income Before Taxes and Minority Interests    131,447           23.3%      34.3%   97,909       22.4%
Taxes                                          19,742                              15,849
-----------------------------------------------------------------------------------------------------
Income Before Minority Interests              111,705                              82,060
Minority interests                                 92                                 474
-----------------------------------------------------------------------------------------------------
NET INCOME                                    111,613           19.8%      36.8%   81,586       18.6%
-----------------------------------------------------------------------------------------------------

Comparative figures have been reclassified to conform with current year's
presentation
* Unaudited


                                                 2003           2002   % CHANGE


Basic Earnings per Share (in U.S. dollars)
 - Bearer shares                                 7.05           5.15       37.0%
--------------------------------------------------------------------------------
 - Registered shares                             2.82           2.06       37.0%
--------------------------------------------------------------------------------
 - American depositary shares                    0.18           0.13       37.0%
--------------------------------------------------------------------------------

Diluted Earnings per Share (in U.S. dollars)
 - Bearer shares                                 7.04           5.14       36.8%
--------------------------------------------------------------------------------
 - Registered shares                             2.81           2.06       36.8%
--------------------------------------------------------------------------------
 - American depositary shares                    0.18           0.13       36.8%
--------------------------------------------------------------------------------

Basic earnings per share are calculated in accordance with IAS 33 (Earnings per
Share) by dividing the net income of the group, US$111.6 million (2002 US$81.6
million), by an appropriate number of shares. This is 11,421,622 bearer shares
(2002 11,446,403) and 11,013,040 registered shares (2002 11,013,040). The total
weighted average equivalent number of bearer shares is 15,826,838 (2002
15,851,619) for the three months ended December 31, 2003. As each American
depositary share represents ownership interest in one fortieth of a bearer
share, basic and diluted earnings per American depositary share is calculated as
one fortieth of the earnings per bearer share.

For diluted earnings per share, the total number of bearer shares is adjusted to
assume conversion of all in the money share options granted to employees and
directors. The number of bearer shares used to calculate diluted earnings per
share is 11,495,708 (2002 11,457,771).



                                     -more-



CONSOLIDATED INCOME STATEMENTS

TWELVE MONTHS ENDED DECEMBER 31                 2003 *            % OF                  2002       %  of
                                               US$'000        REVENUES   % change    US$'000    Revenues
                                                                                 
Revenues
Product sales                                 1,858,009                      30.6%  1,423,130
Royalty and license income                      160,608                      40.0%    114,705
---------------------------------------------------------------------------------------------------------
TOTAL REVENUES                                2,018,617          100.0%      31.3%  1,537,835      100.0%
---------------------------------------------------------------------------------------------------------
Operating Expenses
Cost of product sales                           279,619                      25.0%    223,751
% of Sales                                         15.0%                                 15.7%
Selling, general and administrative             636,823           31.5%      26.3%    504,248       32.8%
Research and development                        467,779           23.2%      30.6%    358,099       23.3%
Restructuring                                         0            0.0%   (100.0%)     16,303        1.1%
Other operating expense, net                    199,476            9.9%     132.5%     85,811        5.6%
---------------------------------------------------------------------------------------------------------
Total Operating Expenses                      1,583,697           78.5%      33.3%  1,188,212       77.3%
---------------------------------------------------------------------------------------------------------
OPERATING INCOME                                434,920           21.5%      24.4%    349,623       22.7%
---------------------------------------------------------------------------------------------------------
Financial income, net                            44,018                      20.7%     36,476
Other (expense), net                            (19,743)                  -1090.8%     (1,658)
---------------------------------------------------------------------------------------------------------
Total Non Operating Income, Net                  24,275                                34,818
---------------------------------------------------------------------------------------------------------
Income Before Taxes and Minority Interests      459,195           22.7%      19.4%    384,441       25.0%
Taxes                                            68,905                                63,127
---------------------------------------------------------------------------------------------------------
Income Before Minority Interests                390,290                               321,314
Minority interests                                  327                                   536
---------------------------------------------------------------------------------------------------------
NET INCOME                                      389,963           19.3%      21.6%    320,778       20.9%
---------------------------------------------------------------------------------------------------------

Comparative figures have been reclassified to conform with current year's
presentation
* Unaudited


                                                   2003           2002   % CHANGE


Basic Earnings per Share (in U.S. dollars)
----------------------------------------------------------------------------------
 - Bearer shares                                  24.63          20.07       22.7%
----------------------------------------------------------------------------------
 - Registered shares                               9.85           8.03       22.7%
----------------------------------------------------------------------------------
 - American depositary shares                      0.62           0.50       22.7%
----------------------------------------------------------------------------------

Diluted Earnings per Share (in U.S. dollars)
----------------------------------------------------------------------------------
 - Bearer shares                                  24.59          20.04       22.7%
----------------------------------------------------------------------------------
 - Registered shares                               9.84           8.02       22.7%
----------------------------------------------------------------------------------
 - American depositary shares                      0.61           0.50       22.7%
----------------------------------------------------------------------------------

Basic earnings per share are calculated in accordance with IAS 33 (Earnings per
Share) by dividing the net income of the group, US$390.0 million (2002 US$320.8
million), by an appropriate number of shares. This is 11,427,194 bearer shares
(2002 11,580,611) and 11,013,040 registered shares (2002 11,013,040). The total
weighted average equivalent number of bearer shares is 15,832,410 (2002
15,985,826) for the twelve months ended December 31, 2003. As each American
depositary share represents ownership interest in one fortieth of a bearer
share, basic and diluted earnings per American depositary share is calculated as
one fortieth of the earnings per bearer share.

For diluted earnings per share, the total number of bearer shares is adjusted to
assume conversion of all in the money share options granted to employees and
directors. The number of bearer shares used to calculate diluted earnings per
share is 11,452,890 (2002 11,598,154).



                                     -more-



CONSOLIDATED BALANCE SHEETS

As of                                                           DECEMBER 31, 2003 *    December 31, 2002
                                                                            US$ 000              US$ 000
                                                                                
ASSETS
Current Assets
Cash and cash equivalents                                                 1,003,972             686,033
Short-term financial assets                                                 434,810             378,865
Trade accounts receivable                                                   318,388             257,313
Inventories                                                                 319,820             259,477
Prepaid expenses and other current assets                                   220,334             234,709
--------------------------------------------------------------------------------------------------------
Total Current Assets                                                      2,297,324           1,816,397
--------------------------------------------------------------------------------------------------------

Non-Current Assets
Property, plant and equipment                                               701,453             554,509
Long-term financial assets                                                1,104,333             711,201
Intangible assets                                                           259,626             230,117
Deferred tax assets                                                         169,693             126,291
Other long-term assets                                                       39,174              45,763
--------------------------------------------------------------------------------------------------------
Total Non-Current Assets                                                  2,274,279           1,667,881
--------------------------------------------------------------------------------------------------------
TOTAL ASSETS                                                              4,571,603           3,484,278
--------------------------------------------------------------------------------------------------------

LIABILITIES
Current Liabilities
Trade and other payables                                                    338,862             268,089
Short-term financial debt                                                    51,224              93,598
Income taxes                                                                146,086             173,656
Deferred income, current                                                     47,200              18,221
Other current liabilities                                                   170,019             122,985
--------------------------------------------------------------------------------------------------------
Total Current Liabilities                                                   753,391             676,549
--------------------------------------------------------------------------------------------------------

Non-Current Liabilities
Long-term financial debt                                                    532,022              25,857
Deferred tax liabilities                                                     15,919              12,080
Deferred income, non-current                                                174,911             176,507
Provisions and other long-term liabilities                                  213,556             130,922
--------------------------------------------------------------------------------------------------------
Total Non-Current Liabilities                                               936,408             345,366
--------------------------------------------------------------------------------------------------------
Total Liabilities                                                         1,689,799           1,021,915
--------------------------------------------------------------  --------------------  ------------------

--------------------------------------------------------------------------------------------------------
Minority Interests                                                            1,614               1,165
--------------------------------------------------------------------------------------------------------

SHAREHOLDERS' EQUITY
Share capital                                                               253,895             253,416
Share premium                                                             1,002,991             989,141
Treasury shares                                                            (157,642)           (126,460)
Retained earnings                                                         1,669,700           1,364,626
Fair value and other reserves                                                22,711             (44,807)
Cumulative foreign currency translation adjustments                          88,535              25,282
--------------------------------------------------------------------------------------------------------
Total Shareholders' Equity                                                2,880,190           2,461,198
--------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------
Total Liabilities, Minority Interests and Shareholders' Equity            4,571,603           3,484,278
--------------------------------------------------------------------------------------------------------

Comparative figures have been reclassified to conform with current year's presentation.
* Unaudited



                                     -more-



CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY

                                                                                                    CUMULATIVE
                                                                                                       FOREIGN
                                                                                      FAIR VALUE      CURRENCY
                                            SHARE     SHARE    TREASURY    RETAINED    AND OTHER   TRANSLATION
                                          CAPITAL   PREMIUM      SHARES    EARNINGS     RESERVES   ADJUSTMENTS        TOTAL
                                          US$ 000   US $000     US$ 000     US$000       US$ 000       US$ 000      US $000
                                                                                            
Balance as of January 1, 2002             253,137    975,335     (9,222)  1,108,086      (25,135)      (83,287)  2,218,914
---------------------------------------------------------------------------------------------------------------------------
Issue of share capital                        279     13,806        184                                             14,269
Net income for 2002                                                         320,778                                320,778
Purchase of treasury shares                                    (117,422)                                          (117,422)
Dividend for 2001 - bearer shares                                           (46,637)                               (46,637)
Dividend for 2001 - registered shares                                       (17,601)                               (17,601)
Revaluation adjustments                                                                  (19,672)                  (19,672)
Foreign currency translation adjustments                                                               108,569     108,569
---------------------------------------------------------------------------------------------------------------------------
Balance as of December 31, 2002           253,416    989,141   (126,460)  1,364,626      (44,807)       25,282   2,461,198
---------------------------------------------------------------------------------------------------------------------------


Balance as of January 1, 2003             253,416    989,141   (126,460)  1,364,626      (44,807)       25,282   2,461,198
---------------------------------------------------------------------------------------------------------------------------
Issue of share capital                        479     15,129                                                        15,608
Issuance of convertible bond                                                              24,605                    24,605
Issue of treasury shares                              (1,404)    10,844                                              9,440
Written calls                                            125                    820                                    945
Net income for 2003                                                         389,963                                389,963
Purchase of treasury shares                                     (42,026)                                           (42,026)
Dividend for 2002 - bearer shares                                           (61,849)                               (61,849)
Dividend for 2002 - registered shares                                       (23,860)                               (23,860)
Revaluation adjustments                                                                   25,903                    25,903
Recognition of impairment on
  available-for-sale investment                                                           11,265                    11,265
Sale of available-for-sale investment                                                      5,745                     5,745
Foreign currency translation adjustments                                                                63,253      63,253
---------------------------------------------------------------------------------------------------------------------------
BALANCE AS OF DECEMBER 31, 2003*          253,895  1,002,991   (157,642)  1,669,700       22,711        88,535   2,880,190
---------------------------------------------------------------------------------------------------------------------------
* Unaudited



                                     -more-



CONSOLIDATED STATEMENTS OF CASH FLOWS

Twelve months ended December 31                                           2003 *         2002
                                                                         US$ 000      US$ 000
                                                                             
Cash Flows From Operating Activities
Income before taxes and minority interests                               459,195     384,441
Depreciation and amortization                                            133,855     100,552
Financial income                                                         (49,815)    (64,645)
Financial expense                                                         12,963      10,643
Loss on available-for-sale investments                                    20,149          --
Other non-cash items                                                      19,598      17,233
---------------------------------------------------------------------------------------------
Cash Flows From Operating Activities Before Working Capital Changes      595,945     448,224
---------------------------------------------------------------------------------------------

Working Capital Changes
Trade accounts payable, other current liabilities and deferred income    104,497     208,341
Trade accounts receivable                                                (34,245)     (3,968)
Inventories                                                              (41,757)    (32,620)
Prepaid expenses and other current assets                                  8,066     (25,482)
Taxes paid                                                               (89,647)    (62,513)
---------------------------------------------------------------------------------------------
NET CASH FLOWS FROM OPERATING ACTIVITIES                                 542,859     531,982
---------------------------------------------------------------------------------------------

Cash Flows From Investing Activities
Acquisition of subsidiary                                                 (9,651)   (115,092)
Purchase of property, plant and equipment                               (162,527)    (99,144)
Purchase of intangible and other long-term assets                        (30,813)    (25,194)
Purchase of financial assets                                            (439,669)   (860,407)
Other non-current liabilities                                            (15,717)    (10,257)
Proceeds from sale of financial assets                                     8,058     344,362
Disposal of subsidiary, net of cash disposed                                  --       6,628
Proceeds from sale of property, plant and equipment                       11,081      10,488
Interest received                                                         67,324      48,005
---------------------------------------------------------------------------------------------
Net Cash Flows From Investing Activities                                (552,175)   (700,611)
---------------------------------------------------------------------------------------------

Cash Flows From Financing Activities
Proceeds from issuance of share capital                                   13,105      11,610
Proceeds from exercises of stock options                                   7,536       1,454
Premiums received on written calls                                           945          --
Purchase of treasury shares                                              (42,026)   (117,422)
Repayment of bank advances                                               (27,096)    (94,490)
Repayment of long-term debt                                              (23,086)    (17,642)
Issuance of long-term debt                                                53,948          --
Issuance of convertible bond                                             444,820          --
Interest paid                                                             (4,361)     (8,121)
Dividends paid                                                           (85,709)    (64,238)
---------------------------------------------------------------------------------------------
Net Cash Flows From Financing Activities                                 338,486    (288,849)
---------------------------------------------------------------------------------------------
Effect of Exchange Rate Changes on Cash and Cash Equivalents               8,918      12,420
---------------------------------------------------------------------------------------------
Net Increase/(Decrease) in Cash and Cash Equivalents                     317,939    (445,058)
---------------------------------------------------------------------------------------------

Cash and Cash Equivalents
- Beginning of period                                                    686,033   1,131,091
---------------------------------------------------------------------------------------------
- End of period                                                        1,003,972     686,033
---------------------------------------------------------------------------------------------

* Unaudited



                                      -end-

                                   SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.


                                   SERONO S.A.
                                   a Swiss corporation
                                   (Registrant)


February 2, 2004                   By:    /s/ Allan Shaw
                                          ----------------------------
                                   Name:  Allan Shaw
                                   Title: Chief Financial Officer