-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 Cp0WSrwskGyuIiQfyeXrUjLW1ibnbwp7QB/MveXgYjbZ8ZOTS/9RRkQ/eF2zXzD8
 1OEjOHcyK27WDPWzPLw/Ag==

<SEC-DOCUMENT>0001182821-03-000003.txt : 20030523
<SEC-HEADER>0001182821-03-000003.hdr.sgml : 20030523
<ACCEPTANCE-DATETIME>20030523163344
ACCESSION NUMBER:		0001182821-03-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030523
FILED AS OF DATE:		20030523

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ASCENTIAL SOFTWARE CORP
		CENTRAL INDEX KEY:			0000799089
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				943011736
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		50 WASHINGTON STREET
		CITY:			WESTBOROUGH
		STATE:			MA
		ZIP:			01581
		BUSINESS PHONE:		6509266300

	MAIL ADDRESS:	
		STREET 1:		50 WASHINGTON STREET
		CITY:			WESTBOROUGH
		STATE:			MA
		ZIP:			01581

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INFORMIX CORP
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MORRILL ROBERT M
		CENTRAL INDEX KEY:			0001182821

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15325
		FILM NUMBER:		03718457

	BUSINESS ADDRESS:	
		STREET 1:		50 WASHINGTON ST
		STREET 2:		C/O ASCENTIAL SOFTWARE CORPORATE
		CITY:			WESTBOROUGH
		STATE:			MA
		ZIP:			015811021
		BUSINESS PHONE:		5083663888

	MAIL ADDRESS:	
		STREET 1:		ASCENTIAL SOFTWARE CORPORATE
		STREET 2:		50 WASHINGTON ST
		CITY:			WESTBOROUGH
		STATE:			MA
		ZIP:			015811021
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-05-23</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000799089</issuerCik>
        <issuerName>ASCENTIAL SOFTWARE CORP</issuerName>
        <issuerTradingSymbol>ASCL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001182821</rptOwnerCik>
            <rptOwnerName>MORRILL ROBERT M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock</value>
        </securityTitle>
        <transactionDate>
            <value>2003-05-23</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>10000</value>
            </transactionShares>
            <transactionValue>
                <value>3.8</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>1326877</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
                <footnoteId id="F1"/>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>See footnote</value>
                <footnoteId id="F1"/>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock</value>
        </securityTitle>
        <transactionDate>
            <value>2003-05-23</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>40000</value>
            </transactionShares>
            <transactionValue>
                <value>3.75</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>1326877</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
                <footnoteId id="F1"/>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>See footnote</value>
                <footnoteId id="F1"/>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <footnotes>
        <footnote id="F1">Following all of the transactions reported on this Form 4, the reporting person holds 668,158 shares directly and 658,719 shares in trust for the benefit of the reporting person's children.  The reporting person and his wife each serve as trustee over such trusts, and the reporting person has shared voting and shared investment power over the shares held therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Barbara A. Dirsa (by power of attorney)</signatureName>
        <signatureDate>2003-05-23</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----