-----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,
 Ed5r+5nAuGHwZLyM8KcJ5p9lGbrBh5U51GSL2TUCcQlL6mP4R5npq8BqMYGUapl5
 7ZI6GANShsGL7pdFigARXw==

<SEC-DOCUMENT>0000928114-07-000001.txt : 20071126
<SEC-HEADER>0000928114-07-000001.hdr.sgml : 20071126
<ACCEPTANCE-DATETIME>20071126171343
ACCESSION NUMBER:		0000928114-07-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071122
FILED AS OF DATE:		20071126
DATE AS OF CHANGE:		20071126

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MOTHERS WORK INC
		CENTRAL INDEX KEY:			0000896985
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-WOMEN'S CLOTHING STORES [5621]
		IRS NUMBER:				133045573
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		456 N 5TH ST
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19123
		BUSINESS PHONE:		2158732200

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MATTHIAS REBECCA C
		CENTRAL INDEX KEY:			0000928114

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21196
		FILM NUMBER:		071267044

	BUSINESS ADDRESS:	
		STREET 1:		JENKINTOWN PLAZA STE 380
		CITY:			JENKINTOWN
		STATE:			PA
		ZIP:			19046
		BUSINESS PHONE:		2156259259

	MAIL ADDRESS:	
		STREET 1:		224 W WASHINGTON SQ
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19106
</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>2007-11-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000896985</issuerCik>
        <issuerName>MOTHERS WORK INC</issuerName>
        <issuerTradingSymbol>MWRK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000928114</rptOwnerCik>
            <rptOwnerName>MATTHIAS REBECCA C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MOTHERS WORK, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>456 NORTH FIFTH STREET</rptOwnerStreet2>
            <rptOwnerCity>PHILADELPHIA</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19123</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>PRESIDENT, CCO AND ACTING CMO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <transactionDate>
                <value>2007-11-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2952</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.33</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>43422</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <transactionDate>
                <value>2007-11-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2952</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.33</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>40470</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>SEE FOOTNOTE</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">ON NOVEMBER 22, 2006, 20,000 SHARES OF RESTRICTED STOCK WERE ISSUED TO THE REPORTING PERSON BY THE ISSUER.  THESE SHARES VEST IN TWO (2) EQUAL ANNUAL INSTALLMENTS BEGINNING ON NOVEMBER 22, 2007.  ON NOVEMBER 22, 2007, THE REPORTING PERSON TURNED IN 2,952 SHARES OF RESTRICTED STOCK TO SETTLE THE MINIMUM REQUIRED TAX WITHHOLDING OBLIGATIONS ARISING FROM THE NOVEMBER 22, 2007 VESTING OF 10,000 SHARES OF RESTRICTED STOCK.</footnote>
        <footnote id="F2">26,374 SHARES OF COMMON STOCK OF THE ISSUER ARE HELD JOINTLY BY THE REPORTING PERSON AND HER HUSBAND, DAN W. MATTHIAS.</footnote>
        <footnote id="F3">ON NOVEMBER 22, 2006, 20,000 SHARES OF RESTRICTED STOCK WERE ISSUED TO THE REPORTING PERSON'S HUSBAND, DAN W. MATTHIAS.  THESE SHARES VEST IN TWO (2) EQUAL ANNUAL INSTALLMENTS BEGINNING ON NOVEMBER 22, 2007.  THE REPORTING PERSON IS DEEMED TO BENEFICIALLY OWN THE SHARES HELD BY HER HUSBAND.  ON NOVEMBER 22, 2007, DAN W. MATTHIAS TURNED IN 2,952 SHARES OF RESTRICTED STOCK TO SETTLE THE MINIMUM REQUIRED TAX WITHHOLDING OBLIGATIONS ARISING FROM THE NOVEMBER 22, 2007 VESTING OF 10,000 SHARES OF RESTRICTED STOCK.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>REBECCA C. MATTHIAS</signatureName>
        <signatureDate>2007-11-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----