AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 21, 2001
                                                  REGISTRATION NO. 333-49830
================================================================================
                     SECURITIES AND EXCHANGE COMMISSION
                           WASHINGTON, D.C. 20549
                        ----------------------------
                      Post-Effective Amendment No. 1
                                    to
                                  FORM S-4
          REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
                       ----------------------------

                 MINNESOTA MINING AND MANUFACTURING COMPANY
  (Exact name of registrant as specified in its articles of incorporation)

       DELAWARE                     3290                   41-0417775
   (State or other           (Primary Standard           (IRS Employer
   jurisdiction of              Industrial             Identification No.)
   incorporation or           Classification
    organization)               Code Number)
                       ----------------------------

                                              GREGG M. LARSON, ESQ.
                                           ASSISTANT GENERAL COUNSEL,
         3M CENTER                            ASSISTANT SECRETARY
  ST. PAUL, MINNESOTA 55144          MINNESOTA MINING AND MANUFACTURING COMPANY
      (651) 733-1110                                3M CENTER
 (Address, including zip code,              ST. PAUL, MINNESOTA 55144
and telephone number, including                   (651) 733-1110
  area code, of registrant's          (Name and address, including zip code,
 principal executive offices)            and telephone number, including
                                         area code, of agent for service)
                       ----------------------------



                                                             COPIES TO:

                                                                                         
           JEAN E. HANSON, ESQ.                          GREGG M. LARSON, ESQ.                  BERKLEY W. DUCK III, ESQ.
FRIED, FRANK, HARRIS, SHRIVER & JACOBSON              ASSISTANT GENERAL COUNSEL,                        ICE MILLER
           ONE NEW YORK PLAZA                             ASSISTANT SECRETARY                      ONE AMERICAN SQUARE
        NEW YORK, NEW YORK 10004              MINNESOTA MINING AND MANUFACTURING COMPANY                BOX 82001
           TEL: (212) 859-8000                                 3M CENTER                       INDIANAPOLIS, IN 46282-0002
           FAX: (212) 859-4000                          ST. PAUL, MN 55144-1000                    TEL: (317) 236-2100
                                                          TEL: (651) 733-1110                      FAX: (317) 236-2219
                                                          FAX: (651) 736-9469

                       ----------------------------

APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE OF SECURITIES TO THE
PUBLIC: As soon as practicable after the effectiveness of this Registration
Statement and the effective time of the merger described herein.

          If the securities being registered on this Form are being offered
in connection with the formation of a holding company and there is
compliance with General Instruction G, check the following box. |_|

          If this Form is filed to register additional securities for an
offering pursuant to Rule 462(b) under the Securities Act, check the
following box and list the Securities Act registration statement number of
the earlier effective registration statement for the same offering. |_|

          If this Form is a post-effective amendment filed pursuant to Rule
462(d) under the Securities Act, check the following box and list the
Securities Act registration statement number of the earlier effective
registration statement for the same offering. |x|

                             Explanatory Note:

Minnesota Mining and Manufacturing Company is filing this Post-Effective
Amendment No. 1 for the sole purpose of filing the additional tax opinion
delivered at the closing of the merger as an exhibit to this Registration
Statement, which it undertook to do in the final proxy statement/prospectus
included in Amendment No. 1 to this Registration Statement.

                                  PART II

                   INFORMATION NOT REQUIRED IN PROSPECTUS


ITEM 21.  EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

(a)  Exhibits.

       Exhibit Number                                               Description

          ##2.1          Agreement and Plan of Merger, dated as of October
                         2, 2000, among Minnesota Mining and Manufacturing
                         Company, Barbados Acquisition, Inc. and Robinson
                         Nugent, Inc.

           *3.1          Certificate of Incorporation, as amended as of May
                         19, 2000

          **3.2          Bylaws, as amended as of November 11, 1996

         ***4.1          Medium-term notes

           #5.1          Opinion of Gregg M. Larson, Assistant General
                         Counsel of 3M, as to the legality of the
                         securities being registered and consent to the use
                         of the opinion in this registration statement

          ##8.1          Opinion of Fried, Frank, Harris, Shriver &
                         Jacobson regarding certain federal income tax
                         consequences described in the proxy
                         statement/prospectus

            8.2          Closing tax opinion of Fried, Frank, Harris,
                         Shriver & Jacobson

          ##9.1          Voting and Stock Option Agreement among 3M,
                         Robinson Nugent, Inc., Samuel C. Robinson, James
                         W. Robinson, Patrick C. Duffy and Larry W. Burke,
                         dated October 2, 2000

          +10.1          1997 Management Stock Ownership Program

         ++10.2          Profit sharing plan, performance unit plan and
                         other compensation arrangements

          #15            Awareness letter from PricewaterhouseCoopers LLP,
                         independent auditors for Minnesota Mining and
                         Manufacturing Company, regarding unaudited interim
                         consolidated financial information

         ##23.1          Consent of PricewaterhouseCoopers LLP

         ##23.2          Consent of Deloitte & Touche LLP (independent
                         auditors for Robinson Nugent, Inc.)

         ##23.3          Consent of Fried, Frank, Harris, Shriver &
                         Jacobson (included in exhibit 8.1)

         ##24            Power of Attorney

         ##99.1          Form of proxy for the Special Meeting of
                         Shareholders of Robinson Nugent, Inc.

--------------------
    *          Incorporated by reference to 3M's Current Report on Form
               8-K, filed with the SEC on July 27, 2000, as amended.

   **          Incorporated by reference to 3M's Current Report on Form 8-K
               filed with the SEC on November 20, 1996.

  ***          Incorporated by reference to 3M's Registration Statement on
               Form S-3 filed with the SEC on June 15, 1999. (Registration
               No. 33-29329)

    +          Incorporated by reference to 3M's Registration Statement
               on Form S-8 filed with the SEC on July 2, 1997.

   ++          Incorporated by reference in written description contained
               in 3M's Definitive Proxy Statement on Form 14A filed with
               the SEC on March 27, 2000.

    #          Previously filed on November 13, 2000.

   ##          Previously filed on January 11, 2001.




                                 SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it
meets all of the requirements for filing on Form S-4 and has duly caused
this Post-Effective Amendment No. 1 to the Registration Statement No.
333-49830 to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of St. Paul, and State of Minnesota, on the 21st day
of February, 2001.

                                     MINNESOTA MINING AND
                                     MANUFACTURING COMPANY

                                     By:  /s/ Gregg M. Larson
                                          --------------------
                                          Name:   Gregg M. Larson
                                          Title:  Assistant General
                                                  Counsel, Assistant Secretary

     Pursuant to the requirements of the Securities Act of 1993, as
amended, this Post-Effective Amendment No. 1 has been signed by the
following persons in the capacities and on the dates as indicated.

Signature                                       Title

               *                                Chairman of the Board,
---------------------------------------         Chief Executive Officer
      W. James McNerney Jr.                     and Director

               *                                Vice President,
---------------------------------------         Principal Financial
      Robert J. Burgstahler                     and Accounting Officer

               *                                Director
---------------------------------------
       Linda G. Alvarado

               *                                Director
---------------------------------------
        Ronald O. Baukol

               *                                Director
---------------------------------------
        Edward M. Liddy

               *                                Director
---------------------------------------
         Aulana L. Peters

               *                                Director
----------------------------------------
        Rozanne L. Ridgway

               *                                Director
---------------------------------------
          Frank Schrontz

               *                                Director
---------------------------------------
          F. Alan Smith


* By:  /s/ Gregg M. Larson
       -------------------------
       Gregg M. Larson
       Attorney-in-fact
       date:  February 21, 2001



                               EXHIBIT INDEX

       Exhibit Number         Description

           ##2.1         Agreement and Plan of Merger, dated as of October
                         2, 2000, among Minnesota Mining and Manufacturing
                         Company, Barbados Acquisition, Inc. and Robinson
                         Nugent, Inc.


            *3.1         Certificate of Incorporation, as amended as of May
                         19, 2000

           **3.2         Bylaws, as amended as of November 11, 1996

          ***4.1         Medium-term notes

            #5.1         Opinion of Gregg M. Larson, Assistant General
                         Counsel of 3M, as to the legality of the
                         securities being registered and consent to the use
                         of the opinion in this registration statement

           ##8.1         Opinion of Fried, Frank, Harris, Shriver &
                         Jacobson regarding certain federal income tax
                         consequences described in the proxy
                         statement/prospectus

             8.2         Closing tax opinion of Fried, Frank, Harris,
                         Shriver & Jacobson

           ##9.1         Voting and Stock Option Agreement among 3M,
                         Robinson Nugent, Inc., Samuel C. Robinson, James
                         W. Robinson, Patrick C. Duffy and Larry W. Burke,
                         dated October 2, 2000

           +10.1         1997 Management Stock Ownership Program

          ++10.2         Profit sharing plan, performance unit plan and
                         other compensation arrangements

           #15           Awareness letter from PricewaterhouseCoopers LLP,
                         independent auditors for Minnesota Mining and
                         Manufacturing Company, regarding unaudited interim
                         consolidated financial information

          ##23.1         Consent of PricewaterhouseCoopers LLP

          ##23.2         Consent of Deloitte & Touche LLP (independent
                         auditors for Robinson Nugent, Inc.)

          ##23.3         Consent of Fried, Frank, Harris, Shriver &
                         Jacobson (included in exhibit 8.1)

          ##24           Power of Attorney

          ##99.1         Form of proxy for the Special Meeting of
                         Shareholders of Robinson Nugent, Inc.

--------------------
    *     Incorporated by reference to 3M's Current Report on Form 8-K,
          filed with the SEC on July 27, 2000, as amended.

   **     Incorporated by reference to 3M's Current Report on Form 8-K
          filed with the SEC on November 20, 1996.

  ***     Incorporated by reference to 3M's Registration Statement on Form
          S-3 filed with the SEC on June 15, 1999. (Registration No.
          33-29329)

    +     Incorporated by reference to 3M's Registration Statement on Form
          S-8 filed with the SEC on July 2, 1997.

   ++     Incorporated by reference in written description contained in
          3M's Definitive Proxy Statement on Form 14A filed with the SEC on
          March 27, 2000.

    #     Previously filed on November 13, 2000.

   ##     Previously filed on January 11, 2001.



                                                                EXHIBIT 8.2

February 16, 2001

Minnesota Mining and Manufacturing Company
3M Center
St. Paul, Minnesota 55114

Robinson Nugent, Inc.
800 East Eighth Street
New Albany, Indiana  47151

Ladies and Gentlemen:

     We have acted as special counsel to Minnesota Mining and Manufacturing
Company ("3M"), a Delaware corporation, in connection with the proposed
merger (the "Merger") of Barbados Acquisition, Inc. ("Merger Sub"), an
Indiana corporation and a wholly-owned subsidiary of 3M, with and into
Robinson Nugent, Inc. ("Robinson Nugent"), an Indiana corporation, with
Robinson Nugent surviving the Merger. The Merger will be consummated
pursuant to the Agreement and Plan of Merger, dated as of October 2, 2000,
by and among 3M, Merger Sub, and Robinson Nugent (the "Merger Agreement").
For purposes of this opinion, capitalized terms used and not otherwise
defined herein shall have the meanings ascribed thereto in the Merger
Agreement.

     Pursuant to Section 7.1(f) of the Merger Agreement, you have requested
that we render the opinion set forth below. In reaching the opinion
expressed below, we have reviewed and relied on (i) the Merger Agreement,
(ii) the Registration Statement of 3M on Form S-4 filed in connection with
the Merger (the "Registration Statement"), (iii) the Proxy
Statement/Prospectus of 3M and Robinson Nugent, dated January 11, 2001,
with respect to the Merger, (iv) representations made by 3M and Robinson
Nugent contained, respectively, in the certificates of the officers of 3M
and Robinson Nugent dated the date hereof (the "Officer's Certificates"),
and (v) such other documents, information and materials as we have deemed
necessary or appropriate. In reviewing these documents, we have assumed the
authenticity of original documents, the accuracy of copies, the genuineness
of signatures, and the legal capacity of signatories.

     In addition, we have assumed that (i) all parties to the Merger
Agreement and to any other documents reviewed by us, have acted, and will
act, in accordance with the terms of the Merger Agreement and such other
documents, and (ii) the Merger will be consummated at the Effective Time
pursuant to the terms and conditions set forth in the Merger Agreement
without the waiver or modification of any such terms and conditions.
Furthermore, we have assumed, without independent investigation or
verification, that (i) all representations contained in the Merger
Agreement, as well as those representations contained in the Officer's
Certificates are true, accurate and complete in all respects at the
Effective Time; and (ii) any representations in the Officer's Certificates
"to the best knowledge of" or similarly qualified are true, accurate and
complete in all respects at the Effective Time without such qualification.

     The opinion expressed herein is based upon current provisions of the
Internal Revenue Code of 1986, as amended (the "Code"), currently
applicable Treasury regulations, and existing judicial decisions and
administrative pronouncements, all of which are subject to change at any
time, possibly with retroactive effect. We assume no obligation to modify
or supplement this opinion if, after the date hereof, any such provisions,
Treasury regulations, decisions or pronouncements change or we become aware
of any facts that might change our opinion or for any other reason. If
there is any change in the applicable law or regulations, or if there is
any new administrative or judicial interpretation of the applicable law or
regulations, any or all of the federal income tax consequences described
herein may become inapplicable.

     This letter addresses only the specific United States federal income
tax consequences of the Merger and does not address any other federal,
state, local, or foreign income, estate, gift, transfer, sales, use or
other tax consequences that may result from the Merger.

     Based upon and subject to the foregoing and to the qualifications and
limitations set forth herein, and in reliance upon the representations and
assumptions described above, we are of the opinion that the Merger will
qualify as a reorganization within the meaning of Section 368(a) of the
Code.

     The foregoing opinion reflects our legal judgment solely on the issue
expressly presented and discussed herein. Our opinion is limited to legal
rather than factual matters. This opinion has no official status or binding
effect of any kind. Accordingly, we cannot assure you that the Internal
Revenue Service or a court having jurisdiction over the issue will agree
with this opinion. Moreover, if the Merger is effected on a factual basis
different from that contemplated in the Merger Agreement, the Proxy
Statement/Prospectus, or the representations contained in the Officer's
Certificates, the opinion expressed herein may be inapplicable.

     The opinion expressed herein is solely for your benefit and may not be
relied on in any manner or for any purpose by any other person or entity or
otherwise referred to in any document without our prior express written
consent. We hereby consent to the filing of this opinion as an exhibit to
the Registration Statement. In giving this consent, we do not hereby admit
that we are in the category of persons whose consent is required under
Section 7 of the Securities Act of 1933, as amended.

     Very truly yours,


     /s/  Fried, Frank, Harris, Shriver & Jacobson
     ------------------------------------------------------
By:  FRIED, FRANK, HARRIS, SHRIVER & JACOBSON