<SUBMISSION>
<ACCESSION-NUMBER>0000032878-04-000055
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20040420
<FILING-DATE>20040426
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ENERGY CONVERSION DEVICES INC
<CIK>0000032878
<ASSIGNED-SIC>3690
<IRS-NUMBER>381749884
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>0630
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>2956 WATERVIEW DRIVE
<CITY>ROCHESTER HILLS
<STATE>MI
<ZIP>48309
<PHONE>248-293-0440
</BUSINESS-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>ENERGY CONVERSION LABORATORIES INC
<DATE-CHANGED>19710603
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Frey Robert I
<CIK>0001288608
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-08403
<FILM-NUMBER>04754202
</FILING-VALUES>
<BUSINESS-ADDRESS>
<PHONE>248-293-0440
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O ENERGY CONVERSION DEVICES, INC.
<STREET2>2956 WATERVIEW DRIVE
<CITY>ROCHESTER HILLS
<STATE>MI
<ZIP>48309
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-04-20</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000032878</issuerCik>
        <issuerName>ENERGY CONVERSION DEVICES INC</issuerName>
        <issuerTradingSymbol>ENER</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001288608</rptOwnerCik>
            <rptOwnerName>Frey Robert I</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2956 WATERVIEW DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ROCHESTER HILLS</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48309</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>12.07</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-04-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This option becomes exercisable as to 40% of the underlying shares one year after the date of grant and as to 20% of the underlying shares after each of the second, third and fourth years of grant.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Robert I Frey</signatureName>
        <signatureDate>2004-04-21</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
