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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001182323-04-000001.txt : 20040128
<SEC-HEADER>0001182323-04-000001.hdr.sgml : 20040128
<ACCEPTANCE-DATETIME>20040128124748
ACCESSION NUMBER:		0001182323-04-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040126
FILED AS OF DATE:		20040128

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BERKERY ROSEMARY T
		CENTRAL INDEX KEY:			0001182323

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07182
		FILM NUMBER:		04548487

	MAIL ADDRESS:	
		STREET 1:		MERRILL LYNCH CORPORATE SECRETARY
		STREET 2:		225 BROADWAY, 17TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10038

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MERRILL LYNCH & CO INC
		CENTRAL INDEX KEY:			0000065100
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		IRS NUMBER:				132740599
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4 WORLD FINANCIAL CTR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10080
		BUSINESS PHONE:		2124491000

	MAIL ADDRESS:	
		STREET 1:		4 WORLD FINANCIAL CTR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10080
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-01-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000065100</issuerCik>
        <issuerName>MERRILL LYNCH &amp; CO INC</issuerName>
        <issuerTradingSymbol>MER</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001182323</rptOwnerCik>
            <rptOwnerName>BERKERY ROSEMARY T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>MERRILL LYNCH &amp; CO., INC.</rptOwnerStreet1>
            <rptOwnerStreet2>4 WORLD FINANCIAL CENTER</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10080</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP and General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-01-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>62987</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>273580</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Appreciation Rights</value>
                <footnoteId id="F4"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>59.85</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-01-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>46557</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-01-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>46557</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>46557</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These Restricted Shares were granted on January 26, 2004 pursuant to the Merrill Lynch &amp; Co., Inc. Long-Term Incentive Compensation Plan.  The Vesting and Restricted Periods for the Restricted Shares shall begin on January 1, 2004 and shall end on January 31, 2008.  Transactions under this plan are exempt under the provisions of Rule 16b-3.</footnote>
        <footnote id="F2">This total also reflects the acquisition of shares of Merrill Lynch &amp; Co., Inc. Common Stock as a result of dividend reinvestments through various Merrill Lynch Plans which is exempt from the reporting requirements under the provisions of Rule 16a-3 and/or Rule 16a-11.</footnote>
        <footnote id="F3">This total also includes 9,600 Book Value Shares.</footnote>
        <footnote id="F4">These stock appreciation rights were granted under the Merrill Lynch &amp; Co., Inc. Long-Term Incentive Compensation Plan.  Transactions under this plan are exempt under the provisions of Rule 16b-3.</footnote>
        <footnote id="F5">11,639 stock appreciation rights will become exercisable after each of 1/26/2005, 1/26/2006 and 1/26/2007.  11,640 stock appreciation rights will become exercisable after 1/26/2008.</footnote>
    </footnotes>

    <remarks>All reported positions have been rounded down to the nearest whole number.</remarks>

    <ownerSignature>
        <signatureName>Rosemary T. Berkery                          (by Michael A. LaMaina, as agent)</signatureName>
        <signatureDate>2004-01-28</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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