<SUBMISSION>
<ACCESSION-NUMBER>0001179110-08-018217
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20081010
<FILING-DATE>20081015
<DATE-OF-FILING-DATE-CHANGE>20081015
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>BENCHMARK ELECTRONICS INC
<CIK>0000863436
<ASSIGNED-SIC>3672
<IRS-NUMBER>742211011
<STATE-OF-INCORPORATION>TX
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>3000 TECHNOLOGY DRIVE
<CITY>ANGLETON
<STATE>TX
<ZIP>77515
<PHONE>9798496550
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>3000 TECHNOLOGY DR
<CITY>ANGLETON
<STATE>TX
<ZIP>77515
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>WILLIAMS CLAY C
<CIK>0001248338
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-10560
<FILM-NUMBER>081125706
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>VARCO INTERNATIONAL INC
<STREET2>2000 W SAM HOUSTON PKY SOUTH STE 1700
<CITY>HOUSTON
<STATE>TX
<ZIP>77042
<PHONE>281-953-2233
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2008-10-10</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000863436</issuerCik>
        <issuerName>BENCHMARK ELECTRONICS INC</issuerName>
        <issuerTradingSymbol>BHE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001248338</rptOwnerCik>
            <rptOwnerName>WILLIAMS CLAY C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7909 PARKWOOD CIRCLE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.27</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2008-10-10</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-10-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>Clay C Williams</signatureName>
        <signatureDate>2008-10-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
