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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 JtKFU3xA0vPWBML5uOiH2h7/D5O3+EZjo8UuBcKUqYSXF1wcDdWFrq5GyWTpxW12
 tTepgSzypO+942P/5JaZJQ==

<SEC-DOCUMENT>0000950117-03-002850.txt : 20030702
<SEC-HEADER>0000950117-03-002850.hdr.sgml : 20030702
<ACCEPTANCE-DATETIME>20030702150108
ACCESSION NUMBER:		0000950117-03-002850
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030701
FILED AS OF DATE:		20030702

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ZIEGLER JOHN B
		CENTRAL INDEX KEY:			0001222674

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12215
		FILM NUMBER:		03771465

	BUSINESS ADDRESS:	
		STREET 1:		QUEST DIAGNOSTICS INC
		STREET 2:		ONE MALCOLM AVE
		CITY:			TETERBORO
		STATE:			NJ
		ZIP:			07608

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a35693.xml
<DESCRIPTION>FORM 4 - JOHN B. ZIEGLER
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-07-01</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0001022079</issuerCik>
        <issuerName>QUEST DIAGNOSTICS INC</issuerName>
        <issuerTradingSymbol>DGX</issuerTradingSymbol>
</issuer>
<reportingOwner>
<reportingOwnerId>
            <rptOwnerCik>0001222674</rptOwnerCik>
            <rptOwnerName>ZIEGLER JOHN B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>0</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
</reportingOwnerRelationship>
</reportingOwner>
<derivativeSecurity>
<securityTitle>
<value>Director Stock Option</value>
<footnoteId id="F1"/>
</securityTitle>
<conversionOrExercisePrice>
<value>63.435</value>
</conversionOrExercisePrice>
<transactionDate>
<value>2003-07-01</value>
</transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>A</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts>
<transactionShares>
<value>368</value>
</transactionShares>
<transactionValue>
<value>63.435</value>
</transactionValue>
<transactionAcquiredDisposedCode>
<value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate>
<value>2003-07-01</value>
</exerciseDate>
<expirationDate>
<value>2013-07-01</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>368</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>368</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</derivativeSecurity>
<footnotes>
<footnote id="F1">Pursuant to a stockholder agreement between the Issuer and SmithKline Beecham (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.  The reporting person is an officer of GlaxoSmithKline.</footnote>
</footnotes>
<ownerSignature>
<signatureName>Leo C. Farrenkopf, Jr., as attorney-in-fact for John B. Ziegler</signatureName>
<signatureDate>2003-07-01</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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