-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 DF5lRIonkYcM8WhDW4Maurq+7pLywU32FUw5+OIIQnpATnRh4Zu1kqrkRfWvskUT
 VECivMbiXWSQ+q5jenuy4w==

<SEC-DOCUMENT>0001140361-08-008377.txt : 20080401
<SEC-HEADER>0001140361-08-008377.hdr.sgml : 20080401
<ACCEPTANCE-DATETIME>20080401172807
ACCESSION NUMBER:		0001140361-08-008377
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080401
FILED AS OF DATE:		20080401
DATE AS OF CHANGE:		20080401

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HYPERDYNAMICS CORP
		CENTRAL INDEX KEY:			0000937136
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				870400335
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		ONE SUGAR CREEK CENTER BLVD., #125
		CITY:			SUGAR LAND
		STATE:			TX
		ZIP:			77478
		BUSINESS PHONE:		7133539400

	MAIL ADDRESS:	
		STREET 1:		ONE SUGAR CREEK CENTER BLVD., #125
		CITY:			SUGAR LAND
		STATE:			TX
		ZIP:			77478

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RAM-Z ENTERPRISES INC
		DATE OF NAME CHANGE:	19950208

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WATTS KENT
		CENTRAL INDEX KEY:			0001038496

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32490
		FILM NUMBER:		08730498

	BUSINESS ADDRESS:	
		STREET 1:		2656 S LOOP WEST
		STREET 2:		STE 103
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77054
		BUSINESS PHONE:		713-353-9400

	MAIL ADDRESS:	
		STREET 1:		9700 BISSONNET
		STREET 2:		SUITE 1700
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77036
</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>2008-04-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000937136</issuerCik>
        <issuerName>HYPERDYNAMICS CORP</issuerName>
        <issuerTradingSymbol>HDY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001038496</rptOwnerCik>
            <rptOwnerName>WATTS KENT</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1 SUGAR CREEK BLVD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 125</rptOwnerStreet2>
            <rptOwnerCity>SUGAR LAND</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77478</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-04-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>40000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2008-04-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2011-04-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock, par value $.001</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>40000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>40000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F2">Options granted in accordance with employment contract.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Kent Watts</signatureName>
        <signatureDate>2008-04-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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