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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0000064463-04-000009.txt : 20040330
<SEC-HEADER>0000064463-04-000009.hdr.sgml : 20040330
<ACCEPTANCE-DATETIME>20040330160629
ACCESSION NUMBER:		0000064463-04-000009
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040329
FILED AS OF DATE:		20040330

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHURCH DALE W
		CENTRAL INDEX KEY:			0001251266

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06890
		FILM NUMBER:		04701154

	MAIL ADDRESS:	
		STREET 1:		9 FRANKLIN STREET
		CITY:			ALEXANDRIA
		STATE:			VA
		ZIP:			22314

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MECHANICAL TECHNOLOGY INC
		CENTRAL INDEX KEY:			0000064463
		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
		IRS NUMBER:				141462255
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		431 NEW KARNER ROAD
		STREET 2:		BUILDING #4
		CITY:			ALBANY
		STATE:			NY
		ZIP:			12205
		BUSINESS PHONE:		5185332200

	MAIL ADDRESS:	
		STREET 1:		431 NEW KARNER ROAD
		STREET 2:		BUILDING #4
		CITY:			ALBANY
		STATE:			NY
		ZIP:			12205
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-03-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000064463</issuerCik>
        <issuerName>MECHANICAL TECHNOLOGY INC</issuerName>
        <issuerTradingSymbol>MKTY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001251266</rptOwnerCik>
            <rptOwnerName>CHURCH DALE W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9 FRANKLIN STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ALEXANDRIA</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22314</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO &amp; Chairman</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-03-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4762</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.25</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>190764</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2250</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares acquired by the Company in connection with a revised tax liability incident to the recipient as a result of the vesting of restricted stock in October 2003.  The Company previously acquired 15,724 shares in connection with the payment of the original tax liability as reported on October 28, 2003.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Cynthia A. Scheuer as Attorney in Fact for Dale W. Church</signatureName>
        <signatureDate>2004-03-30</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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