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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 NS426piiCTF5yKSQ6p73arj7DOgUmtu4XeiNN/5ZWBrQueg5vJExCsLtpUiOtFo/
 IWnEDwvxqUkGcAYmvyT6Ow==

<SEC-DOCUMENT>0001241921-07-000091.txt : 20071105
<SEC-HEADER>0001241921-07-000091.hdr.sgml : 20071105
<ACCEPTANCE-DATETIME>20071105171339
ACCESSION NUMBER:		0001241921-07-000091
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071101
FILED AS OF DATE:		20071105
DATE AS OF CHANGE:		20071105

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MCDERMOTT INTERNATIONAL INC
		CENTRAL INDEX KEY:			0000708819
		STANDARD INDUSTRIAL CLASSIFICATION:	FABRICATED PLATE WORK (BOILER SHOPS) [3443]
		IRS NUMBER:				720593134
		STATE OF INCORPORATION:			R1
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		777 N. ELDRIDGE PARKWAY
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77079
		BUSINESS PHONE:		281-870-5000

	MAIL ADDRESS:	
		STREET 1:		777 N. ELDRIDGE PARKWAY
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77079

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WILKINSON BRUCE W
		CENTRAL INDEX KEY:			0001199548

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08430
		FILM NUMBER:		071214885

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		2818705000

	MAIL ADDRESS:	
		STREET 1:		777 N ELDRIDGE PARKWAY
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77079
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-11-01</periodOfReport>

    <issuer>
        <issuerCik>0000708819</issuerCik>
        <issuerName>MCDERMOTT INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>MDR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001199548</rptOwnerCik>
            <rptOwnerName>WILKINSON BRUCE W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MCDERMOTT INTERNATIONAL, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>777 N. ELDRIDGE PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77079</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-11-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>140000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.8333</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>855794</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-11-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>140000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>715794</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10197</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401 K Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.8333</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-11-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>140000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2012-03-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>140000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>178100</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The sale and underlying exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2007.</footnote>
        <footnote id="F2">The stock was sold in multiple transactions at the following prices: 500 @ $59.75; 1200 @ $59.78; 800 @ $59.79; 1200 @ $59.80; 200 @ $59.8072; 3400 @ $59.81; 1200 @ $59.82; 800 @ $59.83; 2600 @ $59.84; 1600 @ $59.85; 3300 @ $59.86; 3900 @ $59.87; 5300 @ $59.88; 200 @ $59.8857; 1000 @ $59.89; 2200 @ $59.90; 3300 @ $59.91; 1200 @ $59.92; 1300 @ $59.93; 100 @ $59.9398; 1600 @ $59.94; 4700 @ $59.95; 200 @ $59.9555; 2800 @ $59.96; 100 @ $59.9647; 1600 @ $59.97; 1800 @ $59.98; 1800 @ $59.99; 2400 @ $60; 2363 @ $60.01; 100 @ $60.0121; 3100 @ $60.02; 100 @ $60.0247; 1600 @ $60.03; 800 @ $60.04; 500 @ $60.05; 400 @ $60.06; 2100 @ $60.07; 100 @ $60.0834; 400 @ $60.09; 400 @ $60.10; 200 @ $60.11; 500 @ $60.12; 1600 @ $60.13; 2400 @ $60.15; 900 @ $60.16; 800 @ $60.17; 1900 @ $60.21; 200 @ $60.22; 500 @ $60.24; 500 @ $60.25; 100 @ $60.2531; 700 @ $60.27; 400 @ $60.28; 600 @ $60.29; 100 @ $60.30; 1200 @ $60.31; 400 @ $60.32; 800 @ $60.33; continued on footnote no. 3</footnote>
        <footnote id="F3">continued from footnote no. 2; 400 @ $60.34; 600 @ $60.35; 400 @ $60.36; 200 @ $60.3698; 800 @ $60.37; 200 @ $60.38; 1100 @ $60.39; 200 @ $60.41; 1200 @ $60.42; 1100 @ $60.43; 1000 @ $60.44; 700 @ $60.45; 100 @ $60.452; 100 @ $60.4592; 1500 @ $60.46; 100 @ $60.4611; 100 @ $60.4647; 700 @ $60.47; 400 @ $60.48; 100 @ $60.4849; 800 @ $60.49; 100 @ $60.4916; 100 @ $60.4918; 2400 @ $60.50; 800 @ $60.51; 100 @ $60.5191; 1400 @ $60.52; 200 @ $60.5246; 400 @ $60.53; 100 @ $60.5339; 1300 @ $60.54; 800 @ $60.55; 1100 @ $60.56; 1137 @ $60.57; 100 @ $60.5734; 1600  @ $60.58; 100 @ $60.587; 1900 @ $60.59; 1200 @ $60.60; 1200 @ $60.61; 400 @ $60.62; 100 @ $60.6264; 200 @ $60.6399; 400 @ $60.64; 900 @ $60.65; 800 @ $60.66; 400 @ $60.68; 800 @ $60.70; 2500 @ $60.71; 900 @ $60.74; 1200 @ $60.75; 400 @ $60.77; 3400 @ $60.79; 100 @ $60.7993; 1000 @ $60.80; 400 @ $60.81; 100 @ $60.8108; 800 @ $60.82; 700 @ $60.83; 100 @ $60.833; 400 @ $60.84; 100 @ $60.85; continued on footnote no. 4</footnote>
        <footnote id="F4">continued from footnote no. 3; 100 @ $60.8629; 100 @ $60.8753; 400 @ $60.88; 700 @ $60.89; 1600 @ $60.90; 1500 @ $60.91; 400 @ $60.92; 200 @ $60.93; 400 @ $60.94; 100 @ $60.9446; 400 @ $61.01; 400 @ $61.05; 100 @ $61.10; 500 @ $61.14; 500 @ $61.16; 100 @ $61.17; 200 @ $61.18; 400 @ $61.19; 100 @ $61.2276; 400 @ $61.23; 1100 @ $61.25; 200 @ $61.26; 100 @ $61.27; 400 @ $61.31; 400 @ $61.33; 400 @ $61.35; 100 @ $61.3577; 800 @ $61.36; 400 @ $61.37; 800 @ $61.38; 100 @ $61.3835; 400 @ $61.40; 400 @ $61.42; 300 @ $61.43; 400 @ $61.44; 400 @ $61.45; 400 @ $61.46; 400 @ $61.48; 200 @ $61.49; 400 @ $61.51; 100 @ $61.531; 400 @ $61.56; 400 @ $61.59; 400 @ $61.70.</footnote>
        <footnote id="F5">Based upon units held in 401K Plan and the fair market value of Common Stock as of November 1, 2007.</footnote>
        <footnote id="F6">This option vested in three equal installments on March 6, 2003, 2004 and 2005.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Liane K. Hinrichs, by power of attorney</signatureName>
        <signatureDate>2007-11-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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