FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * MOHAPATRA SURYA N   2. Issuer Name and Ticker or Trading Symbol QUEST DIAGNOSTICS INC [DGX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chairman, President & CEO (Last) (First) (Middle) C/O QUEST DIAGNOSTICS INCORPORATED, 1290 WALL STREET WEST 3. Date of Earliest Transaction (Month/Day/Year) 05/22/2006 (Street) LYNDHURST, NJ 07071 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/22/2006   M   32,940 A $ 4.765 145,064 D   Common Stock 05/22/2006   M   52,000 A $ 6.585 197,064 D   Common Stock 05/22/2006   F   6,006 D $ 57.0211 191,058 D   Common Stock 05/22/2006   F   2,753 D $ 57.0211 188,305 D   Common Stock 05/22/2006   S   76,179 D $ 57.0211 112,126 (1) D   Common Stock               4,965 (2) I 401(k)/SDCP

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Stock Options (Right to buy)

$ 4.765

05/22/2006

M

32,940

02/03/2000

02/03/2009

Common Stock

32,940

$ 0

0

D

Stock Options (Right to buy)

$ 6.585

05/22/2006

M

52,000

08/16/2000

08/16/2009

Common Stock

52,000

$ 0

108,000

D

Stock options (Right to buy)

$ 57.0211

05/22/2006

A

2,753

05/22/2007

02/03/2009

Common Stock

2,753

$ 0

2,753

D

Stock options (Right to buy)

$ 57.0211

05/22/2006

A

6,006

05/22/2007

08/16/2009

Common Stock

6,006

$ 0

6,006

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MOHAPATRA SURYA N C/O QUEST DIAGNOSTICS INCORPORATED 1290 WALL STREET WEST LYNDHURST, NJ 07071	X		Chairman, President & CEO

Signatures

Michael E. Prevoznik, atty-in-fact for Surya N. Mohapatra		05/24/2006
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	On June 20, 2005, the Company effected a 2-for-1 stock split of the Common Stock in the form of a 100% stock dividend. All prior holdings, including stock options, have been adjusted to reflect the stock split. This amount also includes 29,542 shares directly beneficially owned by Reporting Person as grantor/trustee of a qualified Grantor Retained Annuity Trust. Reporting Person is in compliance with the Company's executive share ownership guidelines.
(2)	These underlying shares were acquired on a periodic basis by the trustee of the Company's tax qualified Profit Sharing (401(k)) and Supplemental Deferred Compensation Plans. The information was obtained from the plan administrator as of a recent date. The number of shares is based on the account balance of the Company stock fund under the plans (which include some money market instruments) divided by the market price of the Company's stock as of that date.

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