-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 BfpAoHNjSvCNV7gZMMuV0hIXVRzVPm8sgUdUIsxQHRTUs8KvL6wIxpO2pm7FXtus
 fcXoXlU5SJLliq5LUOaxYw==

<SEC-DOCUMENT>0000015615-03-000055.txt : 20031217
<SEC-HEADER>0000015615-03-000055.hdr.sgml : 20031217
<ACCEPTANCE-DATETIME>20031217151451
ACCESSION NUMBER:		0000015615-03-000055
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031216
FILED AS OF DATE:		20031217

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MASTEC INC
		CENTRAL INDEX KEY:			0000015615
		STANDARD INDUSTRIAL CLASSIFICATION:	WATER, SEWER, PIPELINE, COMM AND POWER LINE CONSTRUCTION [1623]
		IRS NUMBER:				650829355
		STATE OF INCORPORATION:			FL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3155 N W 77TH AVE
		CITY:			MIAMI
		STATE:			FL
		ZIP:			33122
		BUSINESS PHONE:		3055991800

	MAIL ADDRESS:	
		STREET 1:		3155 NW 77TH AVENUE
		CITY:			MIAMI
		STATE:			FL
		ZIP:			33122

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BURNUP & SIMS INC
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HEUVELEN JOHN VAN
		CENTRAL INDEX KEY:			0001221440

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08106
		FILM NUMBER:		031059947

	BUSINESS ADDRESS:	
		STREET 1:		363 HIGH STREET
		CITY:			DENVER
		STATE:			CO
		ZIP:			80218
		BUSINESS PHONE:		3037440014

	MAIL ADDRESS:	
		STREET 1:		363 HIGH STREET
		CITY:			DENVER
		STATE:			CO
		ZIP:			80218
</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>2003-12-16</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000015615</issuerCik>
        <issuerName>MASTEC INC</issuerName>
        <issuerTradingSymbol>mtz</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001221440</rptOwnerCik>
            <rptOwnerName>HEUVELEN JOHN VAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>363 HIGH STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80218</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.87</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-12-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>30000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-12-16</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-12-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>30000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>95000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">Exempt stock option grant that vests over three years beginning twelve months after date of grant (12/16/2003). First year 33% vests. Second year an additional 33% vests. Third year remaining 34% vests.</footnote>
        <footnote id="F2">Stock Options granted pursuant to the MasTec, Inc. Amended and Restated 2003 Plan for Non-Employees for no cash consideration.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>/s/ Eliot Abbott</signatureName>
        <signatureDate>2003-12-17</signatureDate>
    </ownerSignature>

</ownershipDocument>

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