-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 CbIHedcc9ui8A6nmJeyd3KoJcilJ4Gpe4904PNqdmLmaU/MywMPQL1UEBNEOjgTk
 7CnMhb0qUfGjzFY3T5CSuA==

<SEC-DOCUMENT>0001209191-09-022821.txt : 20090427
<SEC-HEADER>0001209191-09-022821.hdr.sgml : 20090427
<ACCEPTANCE-DATETIME>20090427130710
ACCESSION NUMBER:		0001209191-09-022821
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090303
FILED AS OF DATE:		20090427
DATE AS OF CHANGE:		20090427

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MERCK & CO INC
		CENTRAL INDEX KEY:			0000064978
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				221109110
		STATE OF INCORPORATION:			NJ
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE MERCK DR
		STREET 2:		P O BOX 100
		CITY:			WHITEHOUSE STATION
		STATE:			NJ
		ZIP:			08889-0100
		BUSINESS PHONE:		9084231688

	MAIL ADDRESS:	
		STREET 1:		ONE MERCK DR
		STREET 2:		PO BOX 100 WS3AB-05
		CITY:			WHITEHOUSE STATION
		STATE:			NJ
		ZIP:			08889-0100

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			McDonough Mark E
		CENTRAL INDEX KEY:			0001388793

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-03305
		FILM NUMBER:		09771928

	MAIL ADDRESS:	
		STREET 1:		MERCK & CO INC
		STREET 2:		ONE MERCK DRIVE PO BOX 100
		CITY:			WHITEHOUSE STATION
		STATE:			NJ
		ZIP:			08889-0100
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>doc4a.xml
<DESCRIPTION>FORM 4/A SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2009-03-03</periodOfReport>

    <dateOfOriginalSubmission>2009-03-05</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000064978</issuerCik>
        <issuerName>MERCK &amp; CO INC</issuerName>
        <issuerTradingSymbol>(MRK)</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001388793</rptOwnerCik>
            <rptOwnerName>McDonough Mark E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE MERCK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 100</rptOwnerStreet2>
            <rptOwnerCity>WHITEHOUSE STATION</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08889-0100</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President and Treasurer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock - Dividend Reinvestment</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>328</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>23.44</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2995.5217</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Amended Form 4 is being filed to correct the number of shares withheld for payment of withholding taxes on the 3/3/09 vesting of restricted stock units and, as a result of that change, corrects the amount of securities beneficially owned.  This Amended Form 4 was necessitated due to a Company administrative error in the original filing.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Debra A. Bollwage as Attorney-in-Fact
for Mark E. McDonough</signatureName>
        <signatureDate>2009-04-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----