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  <link:definitionLink xlink:type="extended" xlink:role="http://www.primoriscorp.com/role/DisclosureContingentEarnoutLiabilitiesDetails">
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    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_RockfordCorporationMember" xlink:label="RockfordCorporationMember" xlink:title="RockfordCorporationMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionAcquireeDomain" xlink:to="RockfordCorporationMember" xlink:title="definition: BusinessAcquisitionAcquireeDomain to RockfordCorporationMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RangeAxis" xlink:label="RangeAxis" xlink:title="RangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="RangeAxis" xlink:to="RangeMember" xlink:title="definition: RangeAxis to RangeMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MinimumMember" xlink:label="MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MinimumMember" xlink:title="definition: RangeMember to MinimumMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MaximumMember" xlink:label="MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MaximumMember" xlink:title="definition: RangeMember to MaximumMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_BusinessAcquisitionContingentConsiderationLineItems" xlink:label="BusinessAcquisitionContingentConsiderationLineItems" xlink:title="BusinessAcquisitionContingentConsiderationLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:label="ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:title="ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:to="BusinessAcquisitionAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable to BusinessAcquisitionAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis" xlink:label="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis" xlink:title="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:to="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable to BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:label="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:title="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis" xlink:to="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:title="definition: BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis to BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:label="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain_2" xlink:title="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis" xlink:to="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain_2" xlink:title="definition: BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodAxis to BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_EarnoutTarget2012Member" xlink:label="EarnoutTarget2012Member" xlink:title="EarnoutTarget2012Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:to="EarnoutTarget2012Member" xlink:title="definition: BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain to EarnoutTarget2012Member" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_EarnoutTarget2013Member" xlink:label="EarnoutTarget2013Member" xlink:title="EarnoutTarget2013Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:to="EarnoutTarget2013Member" xlink:title="definition: BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain to EarnoutTarget2013Member" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_EarnoutTarget2010Member" xlink:label="EarnoutTarget2010Member" xlink:title="EarnoutTarget2010Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:to="EarnoutTarget2010Member" xlink:title="definition: BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain to EarnoutTarget2010Member" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_EarnoutTarget2011Member" xlink:label="EarnoutTarget2011Member" xlink:title="EarnoutTarget2011Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:to="EarnoutTarget2011Member" xlink:title="definition: BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain to EarnoutTarget2011Member" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_EarnoutTargetTwelveMonthPeriodMember" xlink:label="EarnoutTargetTwelveMonthPeriodMember" xlink:title="EarnoutTargetTwelveMonthPeriodMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:to="EarnoutTargetTwelveMonthPeriodMember" xlink:title="definition: BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain to EarnoutTargetTwelveMonthPeriodMember" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_EarnoutTargetEighteenMonthPeriodMember" xlink:label="EarnoutTargetEighteenMonthPeriodMember" xlink:title="EarnoutTargetEighteenMonthPeriodMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain" xlink:to="EarnoutTargetEighteenMonthPeriodMember" xlink:title="definition: BusinessAcquisitionContingentConsiderationEarnoutTargetPeriodDomain to EarnoutTargetEighteenMonthPeriodMember" use="optional" order="6.0" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:to="RangeAxis" xlink:title="definition: ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable to RangeAxis" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionContingentConsiderationEBITDAForMeasuringPotentialCashPayment" xlink:label="BusinessAcquisitionContingentConsiderationEBITDAForMeasuringPotentialCashPayment" xlink:title="BusinessAcquisitionContingentConsiderationEBITDAForMeasuringPotentialCashPayment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionContingentConsiderationEBITDAForMeasuringPotentialCashPayment" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionContingentConsiderationEBITDAForMeasuringPotentialCashPayment" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_BusinessAcquisitionContingentConsiderationPotentialCashPayment" xlink:label="BusinessAcquisitionContingentConsiderationPotentialCashPayment" xlink:title="BusinessAcquisitionContingentConsiderationPotentialCashPayment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionContingentConsiderationPotentialCashPayment" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionContingentConsiderationPotentialCashPayment" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionNumberOfTargetsToBeAchievedForContingentConsiderationPotentialCashPayment" xlink:label="BusinessAcquisitionNumberOfTargetsToBeAchievedForContingentConsiderationPotentialCashPayment" xlink:title="BusinessAcquisitionNumberOfTargetsToBeAchievedForContingentConsiderationPotentialCashPayment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionNumberOfTargetsToBeAchievedForContingentConsiderationPotentialCashPayment" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionNumberOfTargetsToBeAchievedForContingentConsiderationPotentialCashPayment" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionNumberOfPerformanceTargetsForContingentConsiderationCashPayment" xlink:label="BusinessAcquisitionNumberOfPerformanceTargetsForContingentConsiderationCashPayment" xlink:title="BusinessAcquisitionNumberOfPerformanceTargetsForContingentConsiderationCashPayment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionNumberOfPerformanceTargetsForContingentConsiderationCashPayment" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionNumberOfPerformanceTargetsForContingentConsiderationCashPayment" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionContingentConsiderationEBITDAMeausrementPeriodForPotentialCashPayment" xlink:label="BusinessAcquisitionContingentConsiderationEBITDAMeausrementPeriodForPotentialCashPayment" xlink:title="BusinessAcquisitionContingentConsiderationEBITDAMeausrementPeriodForPotentialCashPayment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionContingentConsiderationEBITDAMeausrementPeriodForPotentialCashPayment" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionContingentConsiderationEBITDAMeausrementPeriodForPotentialCashPayment" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionContingentConsiderationPotentialCashCommonStockPayment" xlink:label="BusinessAcquisitionContingentConsiderationPotentialCashCommonStockPayment" xlink:title="BusinessAcquisitionContingentConsiderationPotentialCashCommonStockPayment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionContingentConsiderationPotentialCashCommonStockPayment" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionContingentConsiderationPotentialCashCommonStockPayment" use="optional" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_BusinessAcquisitionContingentConsiderationAtFairValue" xlink:label="BusinessAcquisitionContingentConsiderationAtFairValue" xlink:title="BusinessAcquisitionContingentConsiderationAtFairValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionContingentConsiderationAtFairValue" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionContingentConsiderationAtFairValue" use="optional" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:label="BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:title="BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" use="optional" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:label="BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:title="BusinessAcquisitionCostOfAcquiredEntityCashPaid" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionCostOfAcquiredEntityCashPaid" use="optional" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability" xlink:label="BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability" xlink:title="BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability" use="optional" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_BusinessAcquisitionPurchaseAdditionalCashDue" xlink:label="BusinessAcquisitionPurchaseAdditionalCashDue" xlink:title="BusinessAcquisitionPurchaseAdditionalCashDue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="BusinessAcquisitionPurchaseAdditionalCashDue" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to BusinessAcquisitionPurchaseAdditionalCashDue" use="optional" order="8000.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SharePrice" xlink:label="SharePrice" xlink:title="SharePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="BusinessAcquisitionContingentConsiderationLineItems" xlink:to="SharePrice" xlink:title="definition: BusinessAcquisitionContingentConsiderationLineItems to SharePrice" use="optional" order="8001.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.primoriscorp.com/role/DisclosureRelatedPartyTransactionsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="RelatedPartyTransactionLineItems" xlink:title="RelatedPartyTransactionLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:title="ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="RelatedPartyTransactionLineItems" xlink:to="ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:title="definition: RelatedPartyTransactionLineItems to ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="RelatedPartyTransactionsByRelatedPartyAxis" xlink:title="RelatedPartyTransactionsByRelatedPartyAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="RelatedPartyTransactionsByRelatedPartyAxis" xlink:title="definition: ScheduleOfRelatedPartyTransactionsByRelatedPartyTable to RelatedPartyTransactionsByRelatedPartyAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="RelatedPartyDomain" xlink:title="RelatedPartyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="RelatedPartyDomain" xlink:title="definition: RelatedPartyTransactionsByRelatedPartyAxis to RelatedPartyDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="RelatedPartyDomain_2" xlink:title="RelatedPartyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="RelatedPartyDomain_2" xlink:title="definition: RelatedPartyTransactionsByRelatedPartyAxis to RelatedPartyDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_StockdaleInvestmentGroupIncMember" xlink:label="StockdaleInvestmentGroupIncMember" xlink:title="StockdaleInvestmentGroupIncMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RelatedPartyDomain" xlink:to="StockdaleInvestmentGroupIncMember" xlink:title="definition: RelatedPartyDomain to StockdaleInvestmentGroupIncMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_PlurisLLCMember" xlink:label="PlurisLLCMember" xlink:title="PlurisLLCMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RelatedPartyDomain" xlink:to="PlurisLLCMember" xlink:title="definition: RelatedPartyDomain to PlurisLLCMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_RogerNewnhamMember" xlink:label="RogerNewnhamMember" xlink:title="RogerNewnhamMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RelatedPartyDomain" xlink:to="RogerNewnhamMember" xlink:title="definition: RelatedPartyDomain to RogerNewnhamMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_LemmieRockfordMember" xlink:label="LemmieRockfordMember" xlink:title="LemmieRockfordMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RelatedPartyDomain" xlink:to="LemmieRockfordMember" xlink:title="definition: RelatedPartyDomain to LemmieRockfordMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" xlink:label="RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" xlink:title="RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RelatedPartyTransactionLineItems" xlink:to="RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" xlink:title="definition: RelatedPartyTransactionLineItems to RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="prim-20120930.xsd#prim_RelatedPartyTransactionAgreementAmount" xlink:label="RelatedPartyTransactionAgreementAmount" xlink:title="RelatedPartyTransactionAgreementAmount" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RelatedPartyTransactionLineItems" xlink:to="RelatedPartyTransactionAgreementAmount" xlink:title="definition: RelatedPartyTransactionLineItems to RelatedPartyTransactionAgreementAmount" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RevenueFromRelatedParties" xlink:label="RevenueFromRelatedParties" xlink:title="RevenueFromRelatedParties" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RelatedPartyTransactionLineItems" xlink:to="RevenueFromRelatedParties" xlink:title="definition: RelatedPartyTransactionLineItems to RevenueFromRelatedParties" use="optional" order="4.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.primoriscorp.com/role/DisclosureDividendsAndEarningsPerShareDetails2">
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