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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 NRFX76ZLKcmPZXoJpfSLR0BoVxjCpNXIDQfsCZbl2SsoEYJUx8jD1GE4wxKdzru6
 X3LAu/aTs4hn0I6wsac6Ww==

<SEC-DOCUMENT>0001140361-06-008153.txt : 20060525
<SEC-HEADER>0001140361-06-008153.hdr.sgml : 20060525
<ACCEPTANCE-DATETIME>20060525160639
ACCESSION NUMBER:		0001140361-06-008153
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060523
FILED AS OF DATE:		20060525
DATE AS OF CHANGE:		20060525

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CARRIZO OIL & GAS INC
		CENTRAL INDEX KEY:			0001040593
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				760415919
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1000 LOUISIANA STREET
		STREET 2:		SUITE 1500
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77002
		BUSINESS PHONE:		7133281000

	MAIL ADDRESS:	
		STREET 1:		1000 LOUISIANA STREET
		STREET 2:		SUITE 1500
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77002

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WEBSTER STEVEN A
		CENTRAL INDEX KEY:			0001008023

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-29187-87
		FILM NUMBER:		06867286

	BUSINESS ADDRESS:	
		STREET 1:		3 TEXAS STREET
		STREET 2:		SUITE 1375
		CITY:			SHREVEPORT
		STATE:			LA
		ZIP:			71101
		BUSINESS PHONE:		3184291375

	MAIL ADDRESS:	
		STREET 1:		14701 ST MARY'S LANE
		STREET 2:		SUITE 800
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77079
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-05-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001040593</issuerCik>
        <issuerName>CARRIZO OIL &amp; GAS INC</issuerName>
        <issuerTradingSymbol>CRZO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001008023</rptOwnerCik>
            <rptOwnerName>WEBSTER STEVEN A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1000 LOUISIANA STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1500</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77002</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-05-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2304656</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Includes 8,529 shares of which the reporting person previously reported indirect beneficial ownership as the general partner of a limited partnership. The partnership has distributed all of the shares of the issuer's common stock held by it to its partners.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/Paul F. Boling, attorney-in-fact</signatureName>
        <signatureDate>2006-05-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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