-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0000009521-03-000011.txt : 20031202
<SEC-HEADER>0000009521-03-000011.hdr.sgml : 20031202
<ACCEPTANCE-DATETIME>20031202115758
ACCESSION NUMBER:		0000009521-03-000011
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031202
FILED AS OF DATE:		20031202

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BANCROFT CONVERTIBLE FUND INC
		CENTRAL INDEX KEY:			0000009521
		STANDARD INDUSTRIAL CLASSIFICATION:	UNKNOWN SIC - 0000 [0000]
		IRS NUMBER:				042476994
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1031

	BUSINESS ADDRESS:	
		STREET 1:		65 MADISON AVENUE
		STREET 2:		SUITE 550
		CITY:			MORRISTOWN
		STATE:			NJ
		ZIP:			07960
		BUSINESS PHONE:		(973) 631-1177

	MAIL ADDRESS:	
		STREET 1:		65 MADISON AVENUE
		STREET 2:		SUITE 550
		CITY:			MORRISTOWN
		STATE:			NJ
		ZIP:			07960

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DAVIS DINSMORE MANAGEMENT CO/NJ
		CENTRAL INDEX KEY:			0001014776
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-02151
		FILM NUMBER:		031031807

	BUSINESS ADDRESS:	
		STREET 1:		65 MADISON AVE
		STREET 2:		STE 550
		CITY:			MORRISTOWN
		STATE:			NJ
		ZIP:			07960
		BUSINESS PHONE:		9736311177

	MAIL ADDRESS:	
		STREET 1:		65 MADISON AVE
		STREET 2:		SUITE 550
		CITY:			MORRISTOWN
		STATE:			NJ
		ZIP:			07960
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-12-02</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000009521</issuerCik>
        <issuerName>BANCROFT CONVERTIBLE FUND INC</issuerName>
        <issuerTradingSymbol>BCV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001014776</rptOwnerCik>
            <rptOwnerName>DAVIS DINSMORE MANAGEMENT CO/NJ</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>65 MADISON AVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 550</rptOwnerStreet2>
            <rptOwnerCity>MORRISTOWN</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07960</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Investment Advisor</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-12-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>X</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>467</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>18.32</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3269</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Subscription Rights          (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>18.32</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-12-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>X</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2802</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2003-11-18</value>
            </exerciseDate>
            <expirationDate>
                <value>2003-12-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>467</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">Based on an estimated subscription price per share of 95% of the average of the volume-weighted average sales prices of a share of the BCV's Common Stock on the American Stock Exchange (&quot;AMEX&quot;) on November 13, 2003 and the four preceding trading days.  The actual subscription price per share will be the lesser of (A) 95% of the net asset value per share of the BCV's Common Stock on the AMEX on December 17, 2003, or (B) 95% of the average of the volume-weighted average sales prices of a share of the BCV's Common Stock on the AMEX on December 17, 2003 and the four preceding trading days.</footnote>
        <footnote id="F2">Includes 1,774 shares acquired on various dates in fiscal years 1994 through 2003 under the BCV dividend reinvestment plan.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>/s/ Gary I. Levine</signatureName>
        <signatureDate>2003-12-02</signatureDate>
    </ownerSignature>

</ownershipDocument>

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