<SEC-DOCUMENT>0000807863-12-000003.txt : 20120214
<SEC-HEADER>0000807863-12-000003.hdr.sgml : 20120214
<ACCEPTANCE-DATETIME>20120214204008
ACCESSION NUMBER:		0000807863-12-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120210
FILED AS OF DATE:		20120214
DATE AS OF CHANGE:		20120214

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			THORNTON JOHN M
		CENTRAL INDEX KEY:			0001048185

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35231
		FILM NUMBER:		12613976

	MAIL ADDRESS:	
		STREET 1:		C/O MITEK SYSTEMS, INC.
		STREET 2:		8911 BALBOA AVENUE SUITE B
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92123

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MITEK SYSTEMS INC
		CENTRAL INDEX KEY:			0000807863
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER PERIPHERAL EQUIPMENT, NEC [3577]
		IRS NUMBER:				870418827
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		8911 BALBOA AVE., SUITE B
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92123
		BUSINESS PHONE:		858-503-7810

	MAIL ADDRESS:	
		STREET 1:		8911 BALBOA AVE., SUITE B
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92123
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-02-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000807863</issuerCik>
        <issuerName>MITEK SYSTEMS INC</issuerName>
        <issuerTradingSymbol>MITK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001048185</rptOwnerCik>
            <rptOwnerName>THORNTON JOHN M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MITEK SYSTEMS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>8911 BALBOA AVENUE SUITE B</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92123</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-02-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.09</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2487081</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Note</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Roght to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.09</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2012-02-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-02-25</value>
            </exerciseDate>
            <expirationDate>
                <value>2012-02-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Comprised of 25,000 shares held directly by Mr. Thornton, 25,000 shares held directly by Mr. Thornton's wife, Sally Thornton, and 2,437,081 shares held indirectly through the Thornton Family Trust of 1981.  Mr. and Mrs. Thornton have shared voting and investment control over all of the shares held directly by each of them and the shares held by their family trust.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Fred Hutton, by Power of Attorney</signatureName>
        <signatureDate>2012-02-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
