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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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 Qv8hWv+WcBu4MPdUQJZi9A==

<SEC-DOCUMENT>0000880984-07-000012.txt : 20071120
<SEC-HEADER>0000880984-07-000012.hdr.sgml : 20071120
<ACCEPTANCE-DATETIME>20071120184113
ACCESSION NUMBER:		0000880984-07-000012
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071116
FILED AS OF DATE:		20071120
DATE AS OF CHANGE:		20071120

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ACORN FACTOR, INC.
		CENTRAL INDEX KEY:			0000880984
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER PROGRAMMING SERVICES [7371]
		IRS NUMBER:				222786081
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4 WEST ROCKLAND ROAD
		CITY:			MONTCHANIN
		STATE:			DE
		ZIP:			19710
		BUSINESS PHONE:		3026561708

	MAIL ADDRESS:	
		STREET 1:		4 WEST ROCKLAND ROAD
		CITY:			MONTCHANIN
		STATE:			DE
		ZIP:			19710

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DATA SYSTEMS & SOFTWARE INC
		DATE OF NAME CHANGE:	19931019

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DEFENSE SOFTWARE & SYSTEMS INC
		DATE OF NAME CHANGE:	19930328

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MCMAHON WILLIAM J
		CENTRAL INDEX KEY:			0001162762

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19771
		FILM NUMBER:		071260997

	BUSINESS ADDRESS:	
		STREET 1:		65 GROVE STREET
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02472
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-11-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000880984</issuerCik>
        <issuerName>ACORN FACTOR, INC.</issuerName>
        <issuerTradingSymbol>ACFN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001162762</rptOwnerCik>
            <rptOwnerName>MCMAHON WILLIAM J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ACORN FACTOR, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>4 WEST ROCKLAND ROAD</rptOwnerStreet2>
            <rptOwnerCity>MONTCHANIN</rptOwnerCity>
            <rptOwnerState>DE</rptOwnerState>
            <rptOwnerZipCode>19710</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>CEO of CoaLogix &amp; SCR-Tech</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-11-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.04</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This calculation is based upon the total weighted average price of the total number of shares of common stock purchased by the Reporting Person on November 16, 2007 with respect to the following transactions: (i) 4,500 shares of common stock at $4.03 per share; and (ii) 500 shares of common stock at $4.05 per share.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>William J. McMahon</signatureName>
        <signatureDate>2007-11-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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