<SUBMISSION>
<ACCESSION-NUMBER>0001513162-14-000345
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20140515
<FILING-DATE>20140519
<DATE-OF-FILING-DATE-CHANGE>20140519
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>CLEAN DIESEL TECHNOLOGIES INC
<CIK>0000949428
<ASSIGNED-SIC>3564
<IRS-NUMBER>061393453
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>4567 TELEPHONE ROAD
<STREET2>SUITE 100
<CITY>VENTURA
<STATE>CA
<ZIP>93003
<PHONE>805 639 9458
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>4567 TELEPHONE ROAD
<STREET2>SUITE 100
<CITY>VENTURA
<STATE>CA
<ZIP>93003
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Shea David Eric
<CIK>0001502954
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-33710
<FILM-NUMBER>14855778
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>C/O CLEAN DIESEL TECHNOLOGIES, INC.
<STREET2>4567 TELEPHONE ROAD, SUITE 206
<CITY>VENTURA
<STATE>CA
<ZIP>93003
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
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        <issuerName>CLEAN DIESEL TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>CDTI</issuerTradingSymbol>
    </issuer>

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        <reportingOwnerId>
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            <rptOwnerName>Shea David Eric</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CLEAN DIESEL TECHNOLOGIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>4567 TELEPHONE ROAD, SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>VENTURA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>93003</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
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        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
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            <isTenPercentOwner>0</isTenPercentOwner>
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            <officerTitle>VP Finance &amp; Corp. Controller</officerTitle>
        </reportingOwnerRelationship>
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    <footnotes>
        <footnote id="F1">Shares of Common Stock acquired upon settlement of Restricted Share Units (&quot;RSUs&quot;) granted May 24, 2012 pursuant to the Clean Diesel Technologies, Inc. (&quot;CDTI&quot;) Stock Incentive Plan.</footnote>
        <footnote id="F2">Shares of Common Stock acquired upon settlement of RSUs granted March 20, 2013 pursuant to the CDTI Stock Incentive Plan.</footnote>
        <footnote id="F3">Shares were sold to cover the reporting person's tax obligation in connection with the issuance of the RSUs and conversion into shares of Common Stock.</footnote>
        <footnote id="F4">The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $2.43 to $2.54, inclusive. The reporting person undertakes to provide CDTI, and security holder of CDTI or the staff of the Securities and Exchange Commission upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4.</footnote>
        <footnote id="F5">Each RSU represents a contingent right to receive one share of CDTI common stock.</footnote>
        <footnote id="F6">RSU vests as to 1/3 on each of March 20, 2013, March 20, 2014 and March 20, 2015. Issuance to occur as soon as practicable following the date of vesting and subject to compliance with Issuer's Insider Trading Policy, but in all cases within two and one-half months following the end of the Issuer's tax year that includes the date such RSUs vest. RSUs that have not vested at the time of the reporting person's termination, for any or no reason other than death, will be forfeited.</footnote>
        <footnote id="F7">RSU vests as to 1/3 on each of March 20, 2014, March 20, 2015 and March 20, 2016. Issuance to occur as soon as practicable following the date of vesting and subject to compliance with Issuer's Insider Trading Policy, but in all cases within two and one-half months following the end of the Issuer's tax year that includes the date such RSUs vest. RSUs that have not vested at the time of the reporting person's termination, for any or no reason other than death, will be forfeited.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Kristi Cushing for David E. Shea</signatureName>
        <signatureDate>2014-05-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SUBMISSION>
