<SEC-DOCUMENT>0001022079-17-000018.txt : 20170215
<SEC-HEADER>0001022079-17-000018.hdr.sgml : 20170215
<ACCEPTANCE-DATETIME>20170215163351
ACCESSION NUMBER:		0001022079-17-000018
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20170213
FILED AS OF DATE:		20170215
DATE AS OF CHANGE:		20170215

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:		3 GIRALDA FARMS
		CITY:			MADISON
		STATE:			NJ
		ZIP:			07940
		BUSINESS PHONE:		9735202700

	MAIL ADDRESS:	
		STREET 1:		3 GIRALDA FARMS
		CITY:			MADISON
		STATE:			NJ
		ZIP:			07940

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Cohen Jon R
		CENTRAL INDEX KEY:			0001477972

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12215
		FILM NUMBER:		17615021

	MAIL ADDRESS:	
		STREET 1:		C/O QUEST DIAGNOSTICS INCORPORATED
		STREET 2:		3 GIRALDA FARMS
		CITY:			MADISON
		STATE:			NJ
		ZIP:			07940
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_148719441808397.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-02-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001022079</issuerCik>
        <issuerName>QUEST DIAGNOSTICS INC</issuerName>
        <issuerTradingSymbol>DGX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001477972</rptOwnerCik>
            <rptOwnerName>Cohen Jon R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O QUEST DIAGNOSTICS</rptOwnerStreet1>
            <rptOwnerStreet2>3 GIRALDA FARMS</rptOwnerStreet2>
            <rptOwnerCity>MADISON</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07940</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, Diagnostic Solutions</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-02-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1274</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>93.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>64812</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Disposition of common stock to the issuer solely to cover tax withholding obligations arising from the vesting of a previous grant of restricted shares.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ William J. O'Shaughnessy, Jr., Attorney in Fact for Jon R. Cohen</signatureName>
        <signatureDate>2017-02-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>cohenpoa011717.txt
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>
POWER OF ATTORNEY

Know all by these presents that the undersigned hereby constitutes
and appoints each of William J. O'Shaughnessy, Jr., Michael E.
Prevoznik and Elena H. Radine, signing singly, his true and lawful
attorney-in-fact to:

(1)    execute for and on behalf of the undersigned Forms 3, 4
and 5 in accordance with Section 16(a) of the Securities Exchange Act
of 1934 and the rules thereunder;

(2)    do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete the execution
of any such Form 3, 4 or 5 and the timely filing of such form with the
United States ecurities and Exchange Commission and any other authority;
and

(3) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit
to, in the best interest of, or legally required by, the undersigned, it
being understood that the document executed to this Power of Attorney shall
be in such form and shall contain such terms and conditions as such
attorney-in-fact may approve in his/her discretion.

The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform all and every act and thing whatsoever
requisite, necessary and proper to be done in the exercise of any of the
rights and powers herein granted, as fully to all intents and purposes as
the undersigned might or could do if personally present, with full power
of substitution or revocation, hereby ratifying and confirming all that
such attorney-in-fact, or such attorney-in-fact's substitute or substitutes
shall lawfully do or cause to be done by virtue of this power of attorney
and the rights and powers herein granted.  The undersigned acknowledges
that the foregoing attorneys-in-fact, in serving in such capacity at the
request of the undersigned, are not assuming any of the undersigned's
responsibilities to comply with Section 16 of the Securities Exchange
Act of 1934.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of this 17th day of January, 2017


/s/ Jon R. Cohen, M.D.
JON R. COHEN, M.D.

STATE OF New Jersey    )
            ) ss.
COUNTY OF Morris    )

On this 17th day of January, 2017, before me, DAWN M. LEAHY, the undersigned
notary public, personally appeared JON R. COHEN, M.D., proved to me on the
basis of satisfactory evidence to be the person whose name is subscribed to
the within instrument, and acknowledged to me that he executed the same for
the purposes therein stated.


/s/ Dawn M. Leahy
Notary Public
My Commission Expires: September 12, 2018
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
