-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 PHl7lMRH4jx8oSWQa30u4YeI+U37t11VMuBx7kXep70Hsbk2R1IU6qrAA+sb2bOK
 hm09CWuhjmRcySz7lk8sZg==

<SEC-DOCUMENT>0001082848-08-000003.txt : 20080305
<SEC-HEADER>0001082848-08-000003.hdr.sgml : 20080305
<ACCEPTANCE-DATETIME>20080305123209
ACCESSION NUMBER:		0001082848-08-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080303
FILED AS OF DATE:		20080305
DATE AS OF CHANGE:		20080305

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PROTSCH ELIOT G
		CENTRAL INDEX KEY:			0001209109

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15957
		FILM NUMBER:		08666845

	MAIL ADDRESS:	
		STREET 1:		2612 DIAMONDWOOD DR, S.E.
		CITY:			CEDAR RAPIDS
		STATE:			IA
		ZIP:			52403

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CAPSTONE TURBINE CORP
		CENTRAL INDEX KEY:			0001009759
		STANDARD INDUSTRIAL CLASSIFICATION:	ENGINES & TURBINES [3510]
		IRS NUMBER:				954180883
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		21211 NORDHOFF STREET
		CITY:			CHATSWORTH
		STATE:			CA
		ZIP:			91311
		BUSINESS PHONE:		818-734-5300

	MAIL ADDRESS:	
		STREET 1:		21211 NORDHOFF STREET
		CITY:			CHATSWORTH
		STATE:			CA
		ZIP:			91311
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-03-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001009759</issuerCik>
        <issuerName>CAPSTONE TURBINE CORP</issuerName>
        <issuerTradingSymbol>cpst</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001209109</rptOwnerCik>
            <rptOwnerName>PROTSCH ELIOT G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>21211 NORDHOFF STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHATSWORTH</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91311</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-03-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4278</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.84</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>86797</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Elizabeth M. Reynolds, Power of Attorney for Eliot Protsch, Reporting Person</signatureName>
        <signatureDate>2008-03-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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