-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 VL7v2hAQs2bXGXs1gxqzvpRtCkGu/57iKdu3yrYacDOaHyXaQT7DcTOtKw09k5/0
 1nfX/swnzj7ZPeueXPXjCQ==

<SEC-DOCUMENT>0001252682-07-000001.txt : 20070829
<SEC-HEADER>0001252682-07-000001.hdr.sgml : 20070829
<ACCEPTANCE-DATETIME>20070829152625
ACCESSION NUMBER:		0001252682-07-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070824
FILED AS OF DATE:		20070829
DATE AS OF CHANGE:		20070829

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WESTBOROUGH FINANCIAL SERVICES INC
		CENTRAL INDEX KEY:			0001087843
		STANDARD INDUSTRIAL CLASSIFICATION:	SAVINGS INSTITUTIONS, NOT FEDERALLY CHARTERED [6036]
		IRS NUMBER:				043504121
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		100 E MAIN ST
		CITY:			WESTBOROUGH
		STATE:			MA
		ZIP:			01581
		BUSINESS PHONE:		5083664111

	MAIL ADDRESS:	
		STREET 1:		100 E MAIN ST
		CITY:			WAWESTBOROUGH
		STATE:			MA
		ZIP:			01581

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BALL JAMES N
		CENTRAL INDEX KEY:			0001252682

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-27997
		FILM NUMBER:		071087452

	BUSINESS ADDRESS:	
		STREET 1:		C/O WESTBOROUGH FINANCIAL SERVICES INC
		STREET 2:		100 E MAIN STREET
		CITY:			WESTBOROUGH
		STATE:			MA
		ZIP:			01581
		BUSINESS PHONE:		5083664111
</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>2007-08-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001087843</issuerCik>
        <issuerName>WESTBOROUGH FINANCIAL SERVICES INC</issuerName>
        <issuerTradingSymbol>WFSM.0B</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001252682</rptOwnerCik>
            <rptOwnerName>BALL JAMES N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 EAST MAIN STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WESTBOROUGH</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01581</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, par value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2007-08-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>450</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>35</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2007-08-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>700</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>35</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Jointly with Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>25.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-08-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>U</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>930</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2016-04-24</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>930</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Pursuant to Agreement and Plan of Merger among Assabet Valley Bancorp, HudWest Financial Services, Inc., Hudson Savings Bank and Westborough Bancorp, MHC, Westborough Financial Services, Inc. and The Westborough Bank dated November 13, 2006, as amended.</footnote>
        <footnote id="F2">Restricted stock cancelled in the merger in exchange for a cash payment of $35.00 per share (less any applicable withholdings).</footnote>
        <footnote id="F3">Options granted to the reporting person under the Westborough Financial Services, Inc. 2001 Stock Option Plan. All shares are currently exercisable.</footnote>
        <footnote id="F4">Cancelled in the merger in exchange for a cash payment (less any applicable withholdings) representing the difference between the exercise price and $35.00 per option.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ John L. Casagrande for James N. Ball by Power of Attorney</signatureName>
        <signatureDate>2007-08-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----