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  <!-- Dimension Defaults -->
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  <!-- Dimension Defaults -->
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    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MultiemployerPlansLineItems" xlink:to="us-gaap_MultiemployerPlanPeriodContributions" order="7" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MultiemployerPlansLineItems" xlink:to="mtrx_ContributionsToOtherMultiemployerPlans" order="8" />
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  <!-- Dimension Defaults -->
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MultiemployerPlansTypeDomain" xlink:label="us-gaap_MultiemployerPlansTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_MultiemployerPlanTypeAxis" xlink:to="us-gaap_MultiemployerPlansTypeDomain" order="1" />
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  <!-- Hypercube Definition (Line Items to Hypercube)-->
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ScheduleOfMultiemployerPlansTable" xlink:label="us-gaap_ScheduleOfMultiemployerPlansTable" />
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    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfMultiemployerPlansTable" xlink:to="mtrx_MultiemployerPlanZoneByTypeAxis" order="1" />
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  <!-- Domain Members -->
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    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_MultiemployerPlanZoneByTypeAxis" xlink:label="mtrx_MultiemployerPlanZoneByTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_MultiemployerPlanZoneByTypeDomain" xlink:label="mtrx_MultiemployerPlanZoneByTypeDomain" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_ZoneRedMember" xlink:label="mtrx_ZoneRedMember" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_ZoneYellowMember" xlink:label="mtrx_ZoneYellowMember" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_ZoneGreenMember" xlink:label="mtrx_ZoneGreenMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="mtrx_MultiemployerPlanZoneByTypeAxis" xlink:to="mtrx_MultiemployerPlanZoneByTypeDomain" order="1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="mtrx_MultiemployerPlanZoneByTypeDomain" xlink:to="mtrx_ZoneRedMember" order="1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="mtrx_MultiemployerPlanZoneByTypeDomain" xlink:to="mtrx_ZoneYellowMember" order="2" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="mtrx_MultiemployerPlanZoneByTypeDomain" xlink:to="mtrx_ZoneGreenMember" order="3" />
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  <!-- Hypercube Definition (All)-->
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ScheduleOfMultiemployerPlansTable" xlink:label="us-gaap_ScheduleOfMultiemployerPlansTable" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MultiemployerPlansLineItems" xlink:label="us-gaap_MultiemployerPlansLineItems" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_PercentageOfPlanFunded" xlink:label="mtrx_PercentageOfPlanFunded" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_DescriptionOfFundedPortionOfPlan" xlink:label="mtrx_DescriptionOfFundedPortionOfPlan" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MultiemployerPlansLineItems" xlink:to="mtrx_PercentageOfPlanFunded" order="1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MultiemployerPlansLineItems" xlink:to="mtrx_DescriptionOfFundedPortionOfPlan" order="2" />
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  <!-- Dimension Defaults -->
  <link:definitionLink xlink:type="extended" xlink:role="http://www.matrixservice.com/role/EmployeeBenefitPlansDetailsTextual" xlink:title="06131 - Disclosure - Employee Benefit Plans (Details Textual)">
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_MultiemployerPlanZoneByTypeAxis" xlink:label="mtrx_MultiemployerPlanZoneByTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_MultiemployerPlanZoneByTypeDomain" xlink:label="mtrx_MultiemployerPlanZoneByTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="mtrx_MultiemployerPlanZoneByTypeAxis" xlink:to="mtrx_MultiemployerPlanZoneByTypeDomain" order="1" />
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  <!-- Hypercube Definition (Line Items to Hypercube)-->
  <link:definitionLink xlink:type="extended" xlink:role="http://www.matrixservice.com/role/SegmentInformationDetails" xlink:title="0614 - Disclosure - Segment Information (Details)">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="us-gaap_StatementBusinessSegmentsAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_StatementBusinessSegmentsAxis" order="1" />
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  <!-- Domain Members -->
  <link:definitionLink xlink:type="extended" xlink:role="http://www.matrixservice.com/role/SegmentInformationDetails" xlink:title="0614 - Disclosure - Segment Information (Details)">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="us-gaap_StatementBusinessSegmentsAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SegmentDomain" xlink:label="us-gaap_SegmentDomain" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_ElectricalInfrastructureMember" xlink:label="mtrx_ElectricalInfrastructureMember" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_OilGasAndChemicalMember" xlink:label="mtrx_OilGasAndChemicalMember" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_StorageSolutionsMember" xlink:label="mtrx_StorageSolutionsMember" />
    <link:loc xlink:type="locator" xlink:href="mtrx-20120630.xsd#mtrx_IndustrialMember" xlink:label="mtrx_IndustrialMember" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AllOtherSegmentsMember" xlink:label="us-gaap_AllOtherSegmentsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementBusinessSegmentsAxis" xlink:to="us-gaap_SegmentDomain" order="1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentDomain" xlink:to="mtrx_ElectricalInfrastructureMember" order="1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentDomain" xlink:to="mtrx_OilGasAndChemicalMember" order="2" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentDomain" xlink:to="mtrx_StorageSolutionsMember" order="3" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentDomain" xlink:to="mtrx_IndustrialMember" order="4" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentDomain" xlink:to="us-gaap_AllOtherSegmentsMember" order="5" />
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  <!-- Hypercube Definition (All)-->
  <link:definitionLink xlink:type="extended" xlink:role="http://www.matrixservice.com/role/SegmentInformationDetails" xlink:title="0614 - Disclosure - Segment Information (Details)">
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  <!-- Inheritance for Line Items:  us-gaap:SegmentReportingInformationLineItems-->
  <link:definitionLink xlink:type="extended" xlink:role="http://www.matrixservice.com/role/SegmentInformationDetails" xlink:title="0614 - Disclosure - Segment Information (Details)">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="us-gaap_SegmentReportingInformationLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SegmentReportingInformationProfitLossAbstract" xlink:label="us-gaap_SegmentReportingInformationProfitLossAbstract" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_Revenues" xlink:label="us-gaap_Revenues" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RevenuesFromTransactionsWithOtherOperatingSegmentsOfSameEntity" xlink:label="us-gaap_RevenuesFromTransactionsWithOtherOperatingSegmentsOfSameEntity" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SalesRevenueServicesNet" xlink:label="us-gaap_SalesRevenueServicesNet" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" />
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    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_Revenues" order="2" />
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    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SalesRevenueServicesNet" order="4" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_GrossProfit" order="5" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_OperatingIncomeLoss" order="6" />
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  <!-- Dimension Defaults -->
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  <!-- Hypercube Definition (Line Items to Hypercube)-->
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  <!-- Domain Members -->
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  <!-- Hypercube Definition (All)-->
  <link:definitionLink xlink:type="extended" xlink:role="http://www.matrixservice.com/role/SegmentInformationDetails1" xlink:title="06141 - Disclosure - Segment Information (Details 1)">
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