<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>3</documentType>
<periodOfReport>2003-12-19</periodOfReport>
    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000028630</issuerCik>
        <issuerName>DRS TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>DRS</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001070853</rptOwnerCik>
            <rptOwnerName>MCKEON ROBERT B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VERITAS CAPITAL MANAGEMENT, L.L.C.</rptOwnerStreet1>
            <rptOwnerStreet2>660 MADISON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10021</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>0</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle></officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeHolding><securityTitle><value>Common Stock</value>
</securityTitle>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>2065734</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>By Veritas Capital Management, L.L.C. through The Veritas Capital Fund, L.P.</value>
<footnoteId id="F1"></footnoteId>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeHolding>
</nonDerivativeTable>
<derivativeTable></derivativeTable>
<footnotes><footnote id="F1">Mr. McKeon is one of the two managing members of Veritas Capital Management, L.L.C., a Delaware limited liability company, which is the general partner of The Veritas Capital Fund, L.P., a Delaware limited partnership.</footnote>
</footnotes>
<ownerSignature><signatureName>Robert B. McKeon</signatureName>
<signatureDate>2003-12-19</signatureDate>
</ownerSignature>
</ownershipDocument>

