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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,
 NAsftjqBhkH5lTXZGinrI7hs7TxouaXSpUaCKgAqhniBS95odk5n1+j9JjloODTR
 8J4blXBP2FcfyonoX7e+eQ==

<SEC-DOCUMENT>0000015615-04-000077.txt : 20041029
<SEC-HEADER>0000015615-04-000077.hdr.sgml : 20041029
<ACCEPTANCE-DATETIME>20041029113531
ACCESSION NUMBER:		0000015615-04-000077
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041019
FILED AS OF DATE:		20041029
DATE AS OF CHANGE:		20041029

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Dwyer Robert J
		CENTRAL INDEX KEY:			0001307141

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08106
		FILM NUMBER:		041104844

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		561-659-2255

	MAIL ADDRESS:	
		STREET 1:		880 SOUTH OCEAN BOULEVARD
		CITY:			PALM BEACH
		STATE:			FL
		ZIP:			33480

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:		800 DOUGLAS ROAD
		STREET 2:		12TH FLOOR
		CITY:			CORAL GABLES
		STATE:			FL
		ZIP:			33134
		BUSINESS PHONE:		3055991800

	MAIL ADDRESS:	
		STREET 1:		800 DOUGLAS ROAD
		STREET 2:		12TH FLOOR
		CITY:			CORAL GABLES
		STATE:			FL
		ZIP:			33134

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BURNUP & SIMS INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-10-19</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001307141</rptOwnerCik>
            <rptOwnerName>Dwyer Robert J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>880 SOUTH OCEAN BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALM BEACH</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33480</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>By: /s/ Michael Nearing  For: Robert J Dwyer</signatureName>
        <signatureDate>2004-10-29</signatureDate>
    </ownerSignature>
</ownershipDocument>

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