-----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,
 BZbiAHHeFWHGkB62zDSfTXeL0te+v4RCd4hwPb3272wlpCYRgDMmq11lM7ol+pN/
 JzQ7fj1FQ9cDxdZFTItuKA==

<SEC-DOCUMENT>0001192904-03-000001.txt : 20030603
<SEC-HEADER>0001192904-03-000001.hdr.sgml : 20030603
<ACCEPTANCE-DATETIME>20030603095938
ACCESSION NUMBER:		0001192904-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030530
FILED AS OF DATE:		20030603

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PETERS AULANA L
		CENTRAL INDEX KEY:			0001192904

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07182
		FILM NUMBER:		03729187

	MAIL ADDRESS:	
		STREET 1:		MERRILL LYNCH CORP
		STREET 2:		222 BROADWAY 17TH FL
		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>

    <documentType>4</documentType>

    <periodOfReport>2003-05-30</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001192904</rptOwnerCik>
            <rptOwnerName>PETERS AULANA L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeSecurity>
        <securityTitle>
            <value>ML Stock Unit</value>
            <footnoteId id="F1"/>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>0</value>
            <footnoteId id="F2"/>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-05-30</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>144</value>
                <footnoteId id="F3"/>
            </transactionShares>
            <transactionValue>
                <value>43.13</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>1988-08-08</value>
            <footnoteId id="F1"/>
        </exerciseDate>
        <expirationDate>
            <value>1988-08-08</value>
            <footnoteId id="F1"/>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>144</value>
                <footnoteId id="F3"/>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>16938</value>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <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>
        <footnote id="F3">All reported positions have been rounded down to the nearest whole number.</footnote>
        <footnote id="F4">This total also reflects the reinvestment of dividend equivalents into ML Stock Units pursuant to the terms of the Fee Deferral Plan.  These transactions are exempt from reporting pursuant to Rule 16a-3 and/or 16a-11.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Aulana L. Peters                               (by Michael A. LaMaina, as agent)</signatureName>
        <signatureDate>2003-06-03</signatureDate>
    </ownerSignature>

</ownershipDocument>

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