<SEC-DOCUMENT>0001271163-18-000049.txt : 20180613
<SEC-HEADER>0001271163-18-000049.hdr.sgml : 20180613
<ACCEPTANCE-DATETIME>20180613160813
ACCESSION NUMBER:		0001271163-18-000049
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180611
FILED AS OF DATE:		20180613
DATE AS OF CHANGE:		20180613

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GABELLI MARIO J
		CENTRAL INDEX KEY:			0001185533

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-02151
		FILM NUMBER:		18896803

	MAIL ADDRESS:	
		STREET 1:		C/O GAMCO INVESTORS, INC
		STREET 2:		ONE CORPORATE CENTER
		CITY:			RYE
		STATE:			NY
		ZIP:			10580

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BANCROFT FUND LTD
		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

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BANCROFT CONVERTIBLE FUND INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-06-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000009521</issuerCik>
        <issuerName>BANCROFT FUND LTD</issuerName>
        <issuerTradingSymbol>BCV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001185533</rptOwnerCik>
            <rptOwnerName>GABELLI MARIO J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GAMCO INVESTORS, INC</rptOwnerStreet1>
            <rptOwnerStreet2>ONE CORPORATE CENTER</rptOwnerStreet2>
            <rptOwnerCity>RYE</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10580</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Control Person of Adviser</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2018-06-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>446</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.26</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>56000</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Associated Capital Group, Inc.</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>183967</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The shares reported reflect the total shares owned by Associated Capital Group, Inc. (ACG).  Mario J. Gabelli is the Executive Chairman and controlling shareholder of ACG.  Mr. Gabelli has less than a 100% interest in ACG and disclaims beneficial ownership of the shares held by it which are in excess of his indirect pecuniary interest.</footnote>
        <footnote id="F2">Total includes shares acquired through dividend reinvestment subsequent to the initial purchase.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Agnes Mullady as Attorney-in-Fact for Mario J. Gabelli</signatureName>
        <signatureDate>2018-06-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
