UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               (AMENDMENT NO. 3)*

                   Laboratory Corporation of America Holdings
                                (Name of Issuer)

                                  Common Stock
                         (Title of Class of Securities)

                                   50540R 40 9
                                 (CUSIP Number)

                                December 31, 2005
             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

[X]  Rule 13d-1(b)

[ ]  Rule 13d-1(c)

[ ]  Rule 13d-1(d)

*    The remainder of this cover page shall be filled out for a reporting
     person's initial filing on this form with respect to the subject class of
     securities, and for any subsequent amendment containing information which
     would alter the disclosures provided in a cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).



CUSIP No.50540R 40 9

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1.   Names of Reporting Persons.
     I.R.S. Nos. of above persons (entities only).

     Chieftain Capital Management, Inc. 13-3194313

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2.   Check the Appropriate Box if a Member of a Group (See Instructions)

     a.   Not Applicable

     b.   Not Applicable

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3.   SEC Use Only

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4.   Citizenship or Place of Organization

     New York

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               5.   Sole Voting Power

                    -0-
               -----------------------------------------------------------------
  Number of    6.   Shared Voting Power
   Shares
Beneficially        9,943,708
  Owned by     -----------------------------------------------------------------
    Each       7.   Sole Dispositive Power
  Reporting
Person With:        -0-
               -----------------------------------------------------------------
               8.   Shared Dispositive Power

                    9,943,708

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9.   Aggregate Amount Beneficially Owned by Each Reporting Person

     9,943,708

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10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See
     Instructions)

     Not Applicable

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11.  Percent of Class Represented by Amount in Row (9)

     7.5%

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12.  Type of Reporting Persons (See Instructions)

     IA, CO

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ITEM 1.

           (a) Name of Issuer: Laboratory Corporation of America Holdings

           (b) Address of Issuer's Principal Executive Offices:

                    358 South Main Street
                    Burlington, North Carolina 27215

ITEM 2.

           (a) Name of Person Filing: Chieftain Capital Management, Inc.

           (b) Address of Principal Business Office or, if none, Residence:

                    12 East 49th Street
                    New York, New York 10017

           (c) Citizenship: New York

           (d) Title of Class of Securities: Common Stock

           (e) CUSIP Number: 50540R 40 9

ITEM 3.    IF THIS STATEMENT IS FILED PURSUANT TO SECTIONS 240.13D-1(B) OR
           240.13D-2(B) OR (C), CHECK WHETHER THE PERSON FILING IS A:

           (a) [ ] Broker or dealer registered under Section 15 of the Act (15
               U.S.C. 78o);

           (b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C.
               78c);

           (c) [ ] Insurance company as defined in section 3(a)(19) of the Act
               (15 U.S.C. 78c);

           (d) [ ] Investment company registered under section 8 of the
               Investment Company Act of 1940 (15 U.S.C. 80a-8);

           (e) [X] An investment advisor in accordance with
               Section 240.13d-1(b)(1)(ii)(E);

           (f) [ ] An employee benefit plan or endowment fund in accordance with
               Section 240.13d-1(b)(1)(ii)(F);

           (g) [ ] A parent holding company or control person in accordance with
               Section 240.13d-1(b)(ii)(G);


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           (h) [ ] A savings association as defined in Section 3(b) of the
               Federal Deposit Insurance Act (12 U.S.C. 1813);

           (i) [ ] A church plan that is excluded from the definition of an
               investment company under section 3(c)(14) of the Investment
               Company Act of 1940 (15 U.S.C. 80a-3);

           (j) [ ] Group, in accordance with Section 240.13d-1(b)(1)(ii)(J).

ITEM 4.    Ownership

           (a) Amount beneficially owned: 9,943,708

           (b) Percent of class: 7.5%

           (c) Number of shares as to which the person has:

               (i)  Sole power to vote or to direct the vote: -0-

               (ii) Shared power to vote or to direct the vote: 9,943,708

               (iii) Sole power to dispose or to direct the disposition of: -0-

               (iv) Shared power to dispose or to direct the disposition of:
                    9,943,708

ITEM 5.    OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

           If this statement is being filed to report the fact that as of the
           date hereof the reporting person has ceased to be the beneficial
           owner of more than five percent of the class of securities, check the
           following [ ].

ITEM 6.    OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON

           Chieftain Capital Management, Inc. ("Chieftain") has investment
           discretion with respect to the securities to which this statement
           relates. Chieftain's clients and principals are the direct owners of
           such securities, and Chieftain does not have any economic interest in
           such securities. Such clients and principals have the sole right to
           receive dividends from, and the proceeds from the sale of, such
           securities. No such client or principal has an interest that relates
           to more than 5% of the class.


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ITEM 7.    IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
           THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY

           Not Applicable

ITEM 8.    IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP

           Not Applicable

ITEM 9.    NOTICE OF DISSOLUTION OF GROUP

           Not Applicable

ITEM 10.   CERTIFICATION

          By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were acquired and are held in the
ordinary course of business and were not acquired and are not held for the
purpose of or with the effect of changing or influencing the control of the
issuer of the securities and were not acquired and are not held in connection
with or as a participant in any transaction having that purpose or effect.

                                    SIGNATURE

          After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

                                        February 14, 2006
                                        ----------------------------------------
                                        Date


                                        /s/ Thomas D. Stern
                                        ----------------------------------------
                                        Signature

                                        Thomas D. Stern/Managing Director
                                        ----------------------------------------
                                        Name/Title


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