-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 SbhYbY1j0lMNID7+aWNNwTFL1g7pKoutuuWqRIiqE6bEMiAb9v+DbexQMwLGBND5
 wr49HWTXGRHfbAbQ2jJVqg==

<SEC-DOCUMENT>0001022079-03-000014.txt : 20031002
<SEC-HEADER>0001022079-03-000014.hdr.sgml : 20031002
<ACCEPTANCE-DATETIME>20031002180016
ACCESSION NUMBER:		0001022079-03-000014
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031001
FILED AS OF DATE:		20031002

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			QUEST DIAGNOSTICS INC
		CENTRAL INDEX KEY:			0001022079
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MEDICAL LABORATORIES [8071]
		IRS NUMBER:				161387862
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE MALCOLM AVE
		CITY:			TETERBORO
		STATE:			NJ
		ZIP:			07608
		BUSINESS PHONE:		2013935000

	MAIL ADDRESS:	
		STREET 1:		ONE MALCOLM AVE
		CITY:			TETERBORO
		STATE:			NJ
		ZIP:			07601

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CORNING CLINICAL LABORATORIES INC
		DATE OF NAME CHANGE:	19960903

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GRANT WILLIAM R
		CENTRAL INDEX KEY:			0001016359

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12215
		FILM NUMBER:		03925411

	BUSINESS ADDRESS:	
		STREET 1:		610 FIFTH AVENUE 5TH FLOOR
		STREET 2:		C/O GALEN ASSOCIATES
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10020
		BUSINESS PHONE:		2122184990

	MAIL ADDRESS:	
		STREET 1:		C/O GALEN ASSOCIATES
		STREET 2:		610 FIFTH AVENUE 5TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10020
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001016359d20031002f4s1f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-10-01</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0001022079</issuerCik><issuerName>QUEST DIAGNOSTICS INC</issuerName>        <issuerTradingSymbol>DGX</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001016359</rptOwnerCik><rptOwnerName>GRANT WILLIAM R</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>ONE MALCOLM AVENUE</rptOwnerStreet1><rptOwnerStreet2></rptOwnerStreet2><rptOwnerCity>TETERBORO</rptOwnerCity><rptOwnerState>NJ</rptOwnerState><rptOwnerZipCode>07608</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle></officerTitle><otherText></otherText></reportingOwnerRelationship></reportingOwner><nonDerivativeTable></no
nDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Stock Options (Right to buy)</value></securityTitle><conversionOrExercisePrice><value>61.05</value></conversionOrExercisePrice><transactionDate><value>2003-10-01</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>383</value></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-10-01</value></exerciseDate><expirationDate><value>2013-10-01</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>383</value></underlyingSecurityShares></underlyingSecurity><
postTransactionAmounts><sharesOwnedFollowingTransaction><value>383</value><footnoteId id="F1"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Pursuant to a stockholder agreement between the Issuer and SmithKline Beecham plc (n/k/a GlaxoSmithKline plc.), the reporting person has been elected as a director at the designation of GlaxoSmithKline.  The reporting person disclaims beneficial ownership of the shares of the Issuer beneficially owned by GlaxoSmithKline.</footnote></footnotes><ownerSignature><signatureName>Leo C. Farrenkopf, Jr.</signatureName><signatureDate>2003-10-02</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----