-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 W0UTl25zd8gmI+Mm6C0sZdvAmYZWfb+MMYwrA25nia5tlsYZhmxf8P+M33+I569M
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<SEC-DOCUMENT>0001182338-05-000015.txt : 20050201
<SEC-HEADER>0001182338-05-000015.hdr.sgml : 20050201
<ACCEPTANCE-DATETIME>20050201143504
ACCESSION NUMBER:		0001182338-05-000015
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050131
FILED AS OF DATE:		20050201
DATE AS OF CHANGE:		20050201

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CRIBIORE ALBERTO
		CENTRAL INDEX KEY:			0000936822

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07182
		FILM NUMBER:		05565328

	BUSINESS ADDRESS:	
		STREET 1:		712 FIFTH AVENUE 34TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		2128351350

	MAIL ADDRESS:	
		STREET 1:		C/O SKADDEN ARPS SLATE MEAGHER & FLOM
		STREET 2:		333 WEST WACKER DR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-01-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000936822</rptOwnerCik>
            <rptOwnerName>CRIBIORE ALBERTO</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O 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>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>ML Stock Units</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-01-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>139</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>59.61</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>139</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2635</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person participates in the Merrill Lynch &amp; Co., Inc. Fee Deferral Plan for Non-Employee Directors (the &quot;Fee Deferral Plan&quot;), under which these ML Stock Units were credited.  Transactions under the Fee Deferral Plan are exempt under Rule 16b-3.  The value of each unit is equal to the value of one share of Merrill Lynch &amp; Co., Inc. Common Stock.  ML Stock Units are payable in cash at the end of the deferral period as provided in the Fee Deferral Plan.</footnote>
        <footnote id="F2">1 for 1</footnote>
    </footnotes>

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

    <ownerSignature>
        <signatureName>Alberto Cribiore                          (by Michael A. LaMaina, as agent)</signatureName>
        <signatureDate>2005-02-01</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----