-----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,
 C+7/AcLJ+ImiXZwdbTGBe2LC0jAuqiwDe+INqlEvaXPXprMSL63LgEluVBbDKLen
 ikM7byALzuEL77NSSJDIvA==

<SEC-DOCUMENT>0001283520-04-000002.txt : 20040326
<SEC-HEADER>0001283520-04-000002.hdr.sgml : 20040326
<ACCEPTANCE-DATETIME>20040326095104
ACCESSION NUMBER:		0001283520-04-000002
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040310
FILED AS OF DATE:		20040326

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KLEIN UDO
		CENTRAL INDEX KEY:			0001283520

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-20713
		FILM NUMBER:		04691401

	MAIL ADDRESS:	
		STREET 1:		9640 MEDICAL CENTER DR
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ENTREMED INC
		CENTRAL INDEX KEY:			0000895051
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				581959440
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		9640 MEDICAL CNTR DR
		STREET 2:		STE 200
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850
		BUSINESS PHONE:		3012179858

	MAIL ADDRESS:	
		STREET 1:		9640 MEDICAL CNTR SR
		STREET 2:		STE 200
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>c0001283520d20040326f3s3f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-03-10</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000895051</issuerCik>
        <issuerName>ENTREMED INC</issuerName>
        <issuerTradingSymbol>ENMD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001283520</rptOwnerCik>
            <rptOwnerName>KLEIN UDO</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9640 MEDICAL CENTER DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ROCKVILLE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20850</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President of R&amp;D</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.44</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-09-15</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-09-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>100000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">25% exercisable at grant, 25% exercisable next 3 years</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Udo  Klein</signatureName>
        <signatureDate>2004-03-26</signatureDate>
    </ownerSignature>
</ownershipDocument>

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