<SEC-DOCUMENT>0001022079-17-000184.txt : 20171004
<SEC-HEADER>0001022079-17-000184.hdr.sgml : 20171004
<ACCEPTANCE-DATETIME>20171004170252
ACCESSION NUMBER:		0001022079-17-000184
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20171002
FILED AS OF DATE:		20171004
DATE AS OF CHANGE:		20171004

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RING TIMOTHY M
		CENTRAL INDEX KEY:			0001204666

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12215
		FILM NUMBER:		171122332

	MAIL ADDRESS:	
		STREET 1:		C/O C.R BARD INC
		STREET 2:		730 CENTRAL AVE
		CITY:			MURRAY HILL
		STATE:			NJ
		ZIP:			07974

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:		500 PLAZA DRIVE
		CITY:			SECAUCUS
		STATE:			NJ
		ZIP:			07094
		BUSINESS PHONE:		9735202700

	MAIL ADDRESS:	
		STREET 1:		500 PLAZA DRIVE
		CITY:			SECAUCUS
		STATE:			NJ
		ZIP:			07094

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CORNING CLINICAL LABORATORIES INC
		DATE OF NAME CHANGE:	19960903
</SEC-HEADER>
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<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_150715095923757.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-10-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001204666</rptOwnerCik>
            <rptOwnerName>RING TIMOTHY M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 PLAZA DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SECAUCUS</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07094</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-10-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>330</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>93.52</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>330.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5867.491</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Phantom stock units resulting from elective deferrals of a director's cash compensation pursuant to the Quest Diagnostics Incorporated Amended and Restated Deferred Compensation Plan for Directors and become payable in cash upon the reporting person's termination of service as a director.</footnote>
        <footnote id="F2">Total number of phantom stock units accrued as of the transaction date in the reporting person's deferred compensation account includes phantom stock units credited as a result of dividend reinvestment transactions exempt from reporting pursuant to Rule 16a-11.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ William J. O'Shaughnessy, Jr., attorney in fact for Timothy M. Ring</signatureName>
        <signatureDate>2017-10-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>poaring2017.htm
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>
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<pre>
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
Securities 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
ttorney-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 18th day of January, 2017


/s/ Mark J. Guinan
MARK J. GUINAN

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

On this 18th 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

</pre>
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