-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Q64EUWKCU5pdCxbyXzHz+hTVjEXm0K07i3ZYdfsragfpMSLDlc/bDxH/qRdBeAwa
 E4dW/8toQrdQa5zDwPR4mw==

<SEC-DOCUMENT>0001209191-08-027885.txt : 20080506
<SEC-HEADER>0001209191-08-027885.hdr.sgml : 20080506
<ACCEPTANCE-DATETIME>20080506140043
ACCESSION NUMBER:		0001209191-08-027885
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080502
FILED AS OF DATE:		20080506
DATE AS OF CHANGE:		20080506

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GLOCER THOMAS H
		CENTRAL INDEX KEY:			0001140799

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-03305
		FILM NUMBER:		08805728

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		2123107372

	MAIL ADDRESS:	
		STREET 1:		INSTINET GROUP INC
		STREET 2:		3 TIMES SQ 10TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-05-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001140799</rptOwnerCik>
            <rptOwnerName>GLOCER THOMAS H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>THOMSON REUTERS CORP</rptOwnerStreet1>
            <rptOwnerStreet2>3 TIMES SQUARE - 30TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-02</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>39.22</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5100</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock - Dividend Reinvestment</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Totals reflect the correct account balances (100 shares of common stock previously reported and reflected in the reporting person's dividend reinvestment account should have been reflected in a non-dividend reinvestment account).</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Debra A. Bollwage as Attorney-in-Fact for
Thomas H. Glocer</signatureName>
        <signatureDate>2008-05-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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