<SUBMISSION>
<ACCESSION-NUMBER>0001022079-04-000201
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>2
<PERIOD>20041213
<FILING-DATE>20041215
<DATE-OF-FILING-DATE-CHANGE>20041215
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>PFEIFFER GARY M
<CIK>0001127304
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-12215
<FILM-NUMBER>041205946
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>3027733854
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>1007 MARKET ST
<CITY>WILMINGTON
<STATE>DE
<ZIP>19898
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>QUEST DIAGNOSTICS INC
<CIK>0001022079
<ASSIGNED-SIC>8071
<IRS-NUMBER>161387862
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>ONE MALCOLM AVE
<CITY>TETERBORO
<STATE>NJ
<ZIP>07608
<PHONE>2013935000
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>ONE MALCOLM AVE
<CITY>TETERBORO
<STATE>NJ
<ZIP>07601
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>CORNING CLINICAL LABORATORIES INC
<DATE-CHANGED>19960903
</FORMER-COMPANY>
</ISSUER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-12-13</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001127304</rptOwnerCik>
            <rptOwnerName>PFEIFFER GARY M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1007 MARKET ST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WILMINGTON</rptOwnerCity>
            <rptOwnerState>DE</rptOwnerState>
            <rptOwnerZipCode>19898</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Sirisha Gummaregula, as attorney in fact for Gary M. Pfeiffer</signatureName>
        <signatureDate>2004-12-15</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>pfeipoa-1204.txt
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>
POWER OF ATTORNEY


Know all by these presents, that the
undersigned hereby constiutes and appoints
each of Sirisha Gummaregula, Michael E.
Prevoznik,and Leo C. Farrenkopf, Jr., 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) rules hereunder;

(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 ofsuch attorney-in-fact, may be of benefit
to, in the best interest of, or legally required
by, the undersigned, itbeing understood that the
document executed to this Powerof Attorney shall
be in such form and shall contain such terms and
conditions as such attorney-in-fact may approve
in his 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 ofthe rights
and powers herein granted, as full to all
intents and purposes as the undersigned might
or could do if personally
present,with full power of 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
attorney-in-fact,in serving in such capacity
at the request of the undersigned, are not
assuming any of the undersigned's
responsibilitiesto 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 10th day of December, 2004.
/s/ Gary M. Pfeiffer
Signature
GARY F. PFEIFFER

STATE OF DELAWARE   )
	  	    ):ss.
COUNTY OF NEW CASTLE)

	On this 10TH day of December, 2004, before
me,the subscriber, personally appeared Gary M.
Pfeiffer,to me and known to me to be the same
person described in and who executed the foregoing
instrument,and he duly acknowledged to me that he
executed the same.


/s/ Kathryn G. Kiley
Notary Public, State of Delaware
My Commission Expires
Jan. 5, 2006

</TEXT>
</DOCUMENT>
</SUBMISSION>
