<SEC-DOCUMENT>0001022079-17-000020.txt : 20170215
<SEC-HEADER>0001022079-17-000020.hdr.sgml : 20170215
<ACCEPTANCE-DATETIME>20170215163615
ACCESSION NUMBER:		0001022079-17-000020
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:			Davis J. E.
		CENTRAL INDEX KEY:			0001599837

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12215
		FILM NUMBER:		17615048

	MAIL ADDRESS:	
		STREET 1:		C/O QUEST DIAGNOSTICS
		STREET 2:		3 GIRALDA FARMS
		CITY:			MADISON
		STATE:			NJ
		ZIP:			07940
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_148719456236261.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>0001599837</rptOwnerCik>
            <rptOwnerName>Davis J. E.</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>EVP, General Diagnostics</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>1529</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>93.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29079</value>
                    <footnoteId id="F2"/>
                </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 share units.</footnote>
        <footnote id="F2">The amount includes exempt purchases made under the Company's stock purchase plan since the date of the last filing on Form 4.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ William J. O'Shaughnessy, Jr., attorney-in-fact for James E. Davis</signatureName>
        <signatureDate>2017-02-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>davispoa011717.htm
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>
<!-- Document created using Workiva -->
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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
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 23rd day of January, 2017


/s/ James E. Davis
JAMES E. DAVIS

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

On this 23rd day of January, 2017, before me, DAWN M. LEAHY, the undersigned
notary public, personally appeared JAMES E. DAVIS, 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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