-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Dt6zJvx4UFjEwgjwBKtjZH4iGEGwxHe05xG5QOlm47we8TJFrlOfNmpcYXTtzjC9
 JDc7QIjvytGXcEMAxFZpkQ==

<SEC-DOCUMENT>0001008477-09-000001.txt : 20090522
<SEC-HEADER>0001008477-09-000001.hdr.sgml : 20090522
<ACCEPTANCE-DATETIME>20090522105303
ACCESSION NUMBER:		0001008477-09-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090520
FILED AS OF DATE:		20090522
DATE AS OF CHANGE:		20090522

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MICHALOPOULOS PANOS G
		CENTRAL INDEX KEY:			0001008477

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26056
		FILM NUMBER:		09847416

	MAIL ADDRESS:	
		STREET 1:		500 SPRUCE TREE CENTRE
		STREET 2:		1600 UNIVERSITY AVE WEST
		CITY:			ST PAUL
		STATE:			MN
		ZIP:			55104-3825

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IMAGE SENSING SYSTEMS INC
		CENTRAL INDEX KEY:			0000943034
		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
		IRS NUMBER:				411519168
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		500 SPRUCE TREE CENTRE
		STREET 2:		1600 UNIVERSITY AVE
		CITY:			ST PAUL
		STATE:			MN
		ZIP:			55104-3825
		BUSINESS PHONE:		6516037700

	MAIL ADDRESS:	
		STREET 1:		500 SPRUCE TREE CENTRE
		STREET 2:		1600 UNIVERSITY AVE W.
		CITY:			ST PAUL
		STATE:			MN
		ZIP:			55104
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-05-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000943034</issuerCik>
        <issuerName>IMAGE SENSING SYSTEMS INC</issuerName>
        <issuerTradingSymbol>isns</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001008477</rptOwnerCik>
            <rptOwnerName>MICHALOPOULOS PANOS G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 SPRUCE TREE CENTRE</rptOwnerStreet1>
            <rptOwnerStreet2>1600 UNIVERSITY AVE WEST</rptOwnerStreet2>
            <rptOwnerCity>ST PAUL</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55104-3825</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Non-incentive stock option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-05-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-04-20</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-05-20</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>54000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>/s/ Joanne Ritter, Attorney in Fact for Panos Michalopoulos</signatureName>
        <signatureDate>2009-05-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----