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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>0001260319-03-000006.txt : 20030909
<SEC-HEADER>0001260319-03-000006.hdr.sgml : 20030909
<ACCEPTANCE-DATETIME>20030909140326
ACCESSION NUMBER:		0001260319-03-000006
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030818
FILED AS OF DATE:		20030909

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RATIGAN JAMES A
		CENTRAL INDEX KEY:			0001260319

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-20206
		FILM NUMBER:		03887684

	MAIL ADDRESS:	
		STREET 1:		80 NUKUTA RD
		CITY:			WARRINGTON
		STATE:			PA
		ZIP:			78976

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PERCEPTRON INC/MI
		CENTRAL INDEX KEY:			0000887226
		STANDARD INDUSTRIAL CLASSIFICATION:	OPTICAL INSTRUMENTS & LENSES [3827]
		IRS NUMBER:				382381442
		STATE OF INCORPORATION:			MI
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		47827 HALYARD DRIVE
		CITY:			PLYMOUTH
		STATE:			MI
		ZIP:			48170-2461
		BUSINESS PHONE:		3134144816

	MAIL ADDRESS:	
		STREET 1:		47827 HALYARD DRIVE
		CITY:			PLYMOUTH
		STATE:			MI
		ZIP:			48170-2461
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2003-08-18</periodOfReport>

    <dateOfOriginalSubmission>2003-08-20</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000887226</issuerCik>
        <issuerName>PERCEPTRON INC/MI</issuerName>
        <issuerTradingSymbol>PRCP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001260319</rptOwnerCik>
            <rptOwnerName>RATIGAN JAMES A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>47827 HALYARD DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PLYMOUTH</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48170</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Director Stock Option (Right to Buy)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-08-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-08-18</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-08-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>15000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">On August 18, 2003, the reporting person was granted an option to purchase 15,000 shares of Common Stock under the Directors Stock Option Plan, an exempt plan.

This Amendment to the August 20, 2003 Form 4 reflects revisions to Table II, Column 6, Date Exercisable and Expiration Date and Column 8, Price of Derivative Security.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Sylvia Smith for James A. Ratigan</signatureName>
        <signatureDate>2003-09-09</signatureDate>
    </ownerSignature>

</ownershipDocument>

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