-----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,
 P8cmMwWwYR8RyRCGqvhKH6/oTW6pbZOsElkC0W8A1OiXil7dPbv7maTjtevXfm/K
 nvlnJKYIQYMw6POGLvy1cQ==

<SEC-DOCUMENT>0001127602-08-002738.txt : 20080501
<SEC-HEADER>0001127602-08-002738.hdr.sgml : 20080501
<ACCEPTANCE-DATETIME>20080501143645
ACCESSION NUMBER:		0001127602-08-002738
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080430
FILED AS OF DATE:		20080501
DATE AS OF CHANGE:		20080501

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARSHALL & ILSLEY CORP
		CENTRAL INDEX KEY:			0001399315
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				208995389
		STATE OF INCORPORATION:			WI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		770 NORTH WATER STREET
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53202
		BUSINESS PHONE:		414-765-7700

	MAIL ADDRESS:	
		STREET 1:		770 NORTH WATER STREET
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53202

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NEW M&I CORP
		DATE OF NAME CHANGE:	20070511

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Knickerbocker Beth D
		CENTRAL INDEX KEY:			0001315012

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33488
		FILM NUMBER:		08794053

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(800)342-2265

	MAIL ADDRESS:	
		STREET 1:		MARSHALL & ILSLEY CORPORATION
		STREET 2:		770 N. WATER STREET
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53202
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-04-30</periodOfReport>

    <issuer>
        <issuerCik>0001399315</issuerCik>
        <issuerName>MARSHALL &amp; ILSLEY CORP</issuerName>
        <issuerTradingSymbol>MI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001315012</rptOwnerCik>
            <rptOwnerName>Knickerbocker Beth D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>770 N. WATER ST.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MILWAUKEE</rptOwnerCity>
            <rptOwnerState>WI</rptOwnerState>
            <rptOwnerZipCode>53202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP and Chief Risk Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-04-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>219</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.98</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3064</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6158.4978</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Deferred Compensation Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>484.2161</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Retirement Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Jodi W. Rosenthal, as attorney-in-fact</signatureName>
        <signatureDate>2008-05-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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