<?xml version="1.0" encoding="utf-8"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>
  <periodOfReport>2003-07-16</periodOfReport>
  <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000787648</issuerCik>
        <issuerName>TEXAS REGIONAL BANCSHARES INC</issuerName>
        <issuerTradingSymbol>TRBS</issuerTradingSymbol>
  </issuer>
  <reportingOwner>
    <reportingOwnerId>
            <rptOwnerCik>0001198654</rptOwnerCik>
            <rptOwnerName>MORAN SAN JUANITA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
      <isDirector>0</isDirector>
      <isOfficer>1</isOfficer>
      <isTenPercentOwner>0</isTenPercentOwner>
      <isOther>0</isOther>
      <officerTitle>Controller
</officerTitle>
    </reportingOwnerRelationship>
  </reportingOwner>
  <nonDerivativeSecurity>
    <securityTitle>
      <value>Class A Common Stock</value>
    </securityTitle>
    <transactionDate>
      <value>2003-07-16</value>
    </transactionDate>
    <transactionCoding>
      <transactionFormType>4</transactionFormType>
      <transactionCode>M</transactionCode>
      <equitySwapInvolved>0</equitySwapInvolved>
    </transactionCoding>
    <transactionTimeliness>
      <value/>
    </transactionTimeliness>
    <transactionAmounts>
      <transactionShares>
        <value>1089</value>
      </transactionShares>
      <transactionValue>
        <value>20.0787</value>
      </transactionValue>
      <transactionAcquiredDisposedCode>
        <value>A</value>
      </transactionAcquiredDisposedCode>
    </transactionAmounts>
    <postTransactionAmounts>
      <sharesOwnedFollowingTransaction>
        <value>2178</value>
      </sharesOwnedFollowingTransaction>
    </postTransactionAmounts>
    <ownershipNature>
      <directOrIndirectOwnership>
        <value>D</value>
      </directOrIndirectOwnership>
    </ownershipNature>
  </nonDerivativeSecurity>
  <nonDerivativeSecurity>
    <securityTitle>
      <value>Class A Common Stock</value>
    </securityTitle>
    <transactionDate>
      <value>2003-07-17</value>
    </transactionDate>
    <transactionCoding>
      <transactionFormType>4</transactionFormType>
      <transactionCode>S</transactionCode>
      <equitySwapInvolved>0</equitySwapInvolved>
    </transactionCoding>
    <transactionTimeliness>
      <value/>
    </transactionTimeliness>
    <transactionAmounts>
      <transactionShares>
        <value>1089</value>
      </transactionShares>
      <transactionValue>
        <value>33.90</value>
      </transactionValue>
      <transactionAcquiredDisposedCode>
        <value>D</value>
      </transactionAcquiredDisposedCode>
    </transactionAmounts>
    <postTransactionAmounts>
      <sharesOwnedFollowingTransaction>
        <value>1089</value>
      </sharesOwnedFollowingTransaction>
    </postTransactionAmounts>
    <ownershipNature>
      <directOrIndirectOwnership>
        <value>D</value>
      </directOrIndirectOwnership>
    </ownershipNature>
  </nonDerivativeSecurity>
  <nonDerivativeSecurity>
    <securityTitle>
      <value>Class A Common Stock</value>
    </securityTitle>
    <transactionDate>
      <value>2003-07-17</value>
    </transactionDate>
    <transactionCoding>
      <transactionFormType>4</transactionFormType>
      <transactionCode>A</transactionCode>
      <equitySwapInvolved>0</equitySwapInvolved>
    </transactionCoding>
    <transactionTimeliness>
      <value/>
    </transactionTimeliness>
    <transactionAmounts>
      <transactionShares>
        <value>36.9620</value>
      </transactionShares>
      <transactionValue>
        <value>34.75</value>
      </transactionValue>
      <transactionAcquiredDisposedCode>
        <value>A</value>
        <footnoteId id="F1"/>
      </transactionAcquiredDisposedCode>
    </transactionAmounts>
    <postTransactionAmounts>
      <sharesOwnedFollowingTransaction>
        <value>1457.3764</value>
      </sharesOwnedFollowingTransaction>
    </postTransactionAmounts>
    <ownershipNature>
      <directOrIndirectOwnership>
        <value>I</value>
      </directOrIndirectOwnership>
      <natureOfOwnership>
        <value>By Trustee of ESOP</value>
      </natureOfOwnership>
    </ownershipNature>
  </nonDerivativeSecurity>
  <derivativeSecurity>
    <securityTitle>
      <value>Option (right to buy)</value>
    </securityTitle>
    <conversionOrExercisePrice>
      <value>20.0787</value>
    </conversionOrExercisePrice>
    <transactionDate>
      <value>2003-07-16</value>
    </transactionDate>
    <transactionCoding>
      <transactionFormType>4</transactionFormType>
      <transactionCode>M</transactionCode>
      <equitySwapInvolved>0</equitySwapInvolved>
    </transactionCoding>
    <transactionTimeliness>
      <value/>
    </transactionTimeliness>
    <transactionAmounts>
      <transactionShares>
        <value>1089</value>
      </transactionShares>
      <transactionValue>
        <value>20.0787</value>
      </transactionValue>
      <transactionAcquiredDisposedCode>
        <value>D</value>
      </transactionAcquiredDisposedCode>
    </transactionAmounts>
    <exerciseDate>
      <value>2003-07-01</value>
    </exerciseDate>
    <expirationDate>
      <value>2011-04-15</value>
    </expirationDate>
    <underlyingSecurity>
      <underlyingSecurityTitle>
        <value>Class A Common Stock</value>
      </underlyingSecurityTitle>
      <underlyingSecurityShares>
        <value>1089</value>
      </underlyingSecurityShares>
    </underlyingSecurity>
    <postTransactionAmounts>
      <sharesOwnedFollowingTransaction>
        <value>4989</value>
        <footnoteId id="F2"/>
      </sharesOwnedFollowingTransaction>
    </postTransactionAmounts>
    <ownershipNature>
      <directOrIndirectOwnership>
        <value>D</value>
      </directOrIndirectOwnership>
    </ownershipNature>
  </derivativeSecurity>
  <footnotes>
    <footnote id="F1">The amount represents shares allocated to my account as a participant in the Texas Regional Bancshares, Inc. Amended and Restated Employee Stock Ownership Plan, (the "ESOP").</footnote>
    <footnote id="F2">Granted at various times and at various prices as previously reported.</footnote>
  </footnotes>
  <ownerSignature>
    <signatureName>/s/ San Juanita Moran</signatureName>
    <signatureDate>2003-07-17</signatureDate>
  </ownerSignature>
</ownershipDocument>

