<?xml version="1.0" encoding="us-ascii"?>
<!--XBRL document created with Bowne Tagger. XBRL Parser version 10.0.0.34-->
<!--Based on XBRL 2.1-->
<!--Created on: 5/23/2009 3:52:46 PM-->
<!--Modified on: 5/10/2010 10:40:31 PM-->
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  <annotation>
    <appinfo>
      <link:roleType roleURI="http://quantaservices.com/role/NewAccountingPronouncements" id="NewAccountingPronouncements">
        <link:definition>0203 - Disclosure - New Accounting Pronouncements (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/DebtObligations" id="DebtObligations">
        <link:definition>0206 - Disclosure - Debt Obligations (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/DocumentAndEntityInformation" id="DocumentAndEntityInformation">
        <link:definition>00 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/SubsequentEvent" id="SubsequentEvent">
        <link:definition>0211 - Disclosure - Subsequent Event (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/StockBasedCompensation" id="StockBasedCompensation">
        <link:definition>0208 - Disclosure - Stock-Based Compensation (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/StockholdersEquity" id="StockholdersEquity">
        <link:definition>0207 - Disclosure - Equity (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/SummaryOfSignificantAccountingPolicies" id="SummaryOfSignificantAccountingPolicies">
        <link:definition>0202 - Disclosure - Summary of Significant Accounting Policies (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/BalanceSheetsParenthetical" id="BalanceSheetsParenthetical">
        <link:definition>0111 - Statement - Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/CommitmentsAndContingencies" id="CommitmentsAndContingencies">
        <link:definition>0209 - Disclosure - Commitments and Contingencies (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/SegmentInformation" id="SegmentInformation">
        <link:definition>0210 - Disclosure - Segment Information (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/PerShareInformation" id="PerShareInformation">
        <link:definition>0205 - Disclosure - Per Share Information (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/GoodwillAndOtherIntangibleAssets" id="GoodwillAndOtherIntangibleAssets">
        <link:definition>0204 - Disclosure - Goodwill and Other Intangible Assets (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/BusinessAndOrganization" id="BusinessAndOrganization">
        <link:definition>0201 - Disclosure - Business and Organization (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/StatementsOfCashFlows" id="StatementsOfCashFlows">
        <link:definition>0130 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/StatementsOfOperations" id="StatementsOfOperations">
        <link:definition>0120 - Statement - Condensed Consolidated Statements of Operations (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://quantaservices.com/role/BalanceSheets" id="BalanceSheets">
        <link:definition>0110 - Statement - Condensed Consolidated Balance Sheets (Unaudited)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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