UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

           July 22, 2005           
(Date of earliest event reported)

LABORATORY CORPORATION OF
AMERICA HOLDINGS

(Exact Name of Registrant as Specified in its Charter)
         
DELAWARE   1-11353   13-3757370
  		 
 		  
 
(State or other jurisdiction
of Incorporation) 		  (Commission
File Number)		   (I.R.S. Employer
Identification No.)
         
358 SOUTH MAIN STREET,
BURLINGTON, NORTH CAROLINA 		  27215   336-229-1127
  		 
 		  
 
(Address of principal executive offices)   (Zip Code)
   (Registrant's telephone number including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

ITEM 7.01. Regulation FD Disclosure

On July 22, 2005 — Laboratory Corporation of America® Holdings (LabCorp®) announced that it will begin validation testing of Roche Diagnostics’ AmpliChip™ CYP450 test. The AmpliChip™ CYP450 test has been cleared by the U.S. Food and Drug Administration for diagnostic use. AmpliChip™ CYP450 test results will allow physicians to consider genetic information from patients in selecting medications and doses of medications for a wide variety of common conditions such as cardiac diseases, chronic pain, cancer, and common psychiatric disorders.

Exhibits

99.1 Press Release dated July 22, 2005

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 hereunto duly authorized.

         
  Laboratory Corporation of America Holdings
(Registrant)
 		  
Date: July 25, 2005  By:   /s/Bradford T. Smith    
    Bradford T. Smith, Executive Vice President
and Secretary