-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Br4XGXX6wttx+prUp5VuZvtGpUjkaM8cIIfg5JdAhxj5QvVvLmI/Iz8H2WePtXIo
 PLzdpAD1Ejfney5XTMW+3g==

<SEC-DOCUMENT>0000009521-04-000005.txt : 20040105
<SEC-HEADER>0000009521-04-000005.hdr.sgml : 20040105
<ACCEPTANCE-DATETIME>20040105155156
ACCESSION NUMBER:		0000009521-04-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031231
FILED AS OF DATE:		20040105

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LAKE H TUCKER JR
		CENTRAL INDEX KEY:			0001190034

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-02151
		FILM NUMBER:		04504852

	MAIL ADDRESS:	
		STREET 1:		C/O DAVIS-DINSMORE MANAGEMENT
		STREET 2:		65 MADISON AVE
		CITY:			MORRISTOWN
		STATE:			NJ
		ZIP:			07960

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
</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>2003-12-31</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001190034</rptOwnerCik>
            <rptOwnerName>LAKE H TUCKER JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DAVIS-DINSMORE MANAGEMENT</rptOwnerStreet1>
            <rptOwnerStreet2>65 MADISON AVE</rptOwnerStreet2>
            <rptOwnerCity>MORRISTOWN</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07960</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.82</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>122</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were acquired in the Fund's 2003 Rights Offering pursuant to the Over-Subscription Privilege.  Only shareholders who subscribed for all shares allocated to them in the Primary Subscription were able to participate in the Over-Subscription Privilege.  The 2003 Rights Offering was approved by the Fund's Board of Directors.</footnote>
        <footnote id="F2">Based on the subscription price per share of 95% of the average of the volume-weighted average sales prices of a share of the Fund's Common Stock on the American Stock Exchange (&quot;AMEX&quot;) on December 17, 2003 and the four preceding trading days.</footnote>
        <footnote id="F3">Includes 1 share acquired on December 26, 2003 under the BCV dividend reinvestment plan.</footnote>
        <footnote id="F4">In addition, the reporting person is the indirect beneficial owner of 264 additional shares owned by his wife, which includes 2 shares acquired on December 26, 2003 under the BCV dividend reinvestment plan.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>/s/ Gary I. Levine, attorney-in-fact</signatureName>
        <signatureDate>2004-01-05</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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