-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 H+LkokE4ux2xQ3InVipgTDoHB2imkKPGFB22JTe4wYMJGMybKe7Fg4X1Iu+1kemq
 /eYQiofdBkLi4Hs67VMFng==

<SEC-DOCUMENT>0001241921-08-000004.txt : 20080205
<SEC-HEADER>0001241921-08-000004.hdr.sgml : 20080205
<ACCEPTANCE-DATETIME>20080205165509
ACCESSION NUMBER:		0001241921-08-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080201
FILED AS OF DATE:		20080205
DATE AS OF CHANGE:		20080205

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:		08577593

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		2818705000

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

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
</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>2008-02-01</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>2008-02-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>140000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.845</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>2008-02-01</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>10224</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401k Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.845</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-02-01</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>2011-03-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>140000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>298100</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: 6,300 @ $46.80; 500 @ $46.84; 500 @ $46.91; 100 @ $46.92; 1,400 @ $46.93; 400 @ $46.94; 300 @ $46.95; 1,000 @ $46.96; 400 @ $46.97; 1,300 @ $46.98; 2,000 @ $46.99; 400 @ $47; 503 @ $47.02; 300 @ $47.03; 902 @ $47.04; 1,200 @ $47.05; 400 @ $47.06; 200 @ $47.08; 529 @ $47.09; 200 @ $47.10; 1,900 @ $47.11; 1,500 @ $47.12; 2,700 @ $47.13; 200 @ $47.14; 2,200 @ $47.15; 3,000 @ $47.16; 700 @ $47.17; 971 @ $47.18; 3,000 @ $47.19; 1,495 @ $47.20; 1,100 @ $47.21; 1,600 @ $47.22; 1,300 @ $47.23; 5,000 @ $47.24; 100 @ $47.25; 2,500 @ $47.26; 703 @ $47.27; 2,100 @ $47.29; 1,597 @ $47.30; 2,100 @ $47.31; 1,200 @ $47.32; 1,700 @ $47.34; 1,700 @ $47.35; 1,400 @ $47.36; 500 @  $47.37; 300 @ $47.38; 300 @ $47.39; continued on footnote no. 3</footnote>
        <footnote id="F3">continued from footnote no. 2;  1,500 @ $47.41; 1,000 @ $47.42; 2,600 @ $47.43; 1,100 @ $47.44; 700 @ $47.45; 500 @ $47.46; 2,200 @ $47.47; 1,200 @ $47.48; 1,400 @ $47.49; 100 @ $47.50; 400 @ $47.51; 900 @ $47.52; 700 @ $47.53; 700 @ $47.54; 2,100 @ $47.55; 800 @ $47.57; 100 @ $47.58; 300 @ $47.59; 700 @ $47.60; 1,400 @ $47.61; 3,000 @ $47.63; 400 @ $47.64; 1,400 @ $47.65; 800 @ $47.66; 400 @ $47.67; 900 @ $47.68; 1,900 @ $47.69; 900 @ $47.70; 300 @ $47.71; 200 @ $47.74; 100 @ $47.76; 100 @ $47.77; 2,100 @ $47.78; 1,400 @ $47.79; 300 @ $47.80; 100 @ $47.82; 400 @ $47.83; 2,100 @ $47.87; 500 @ $47.88; 600 @ $47.90; contintued on footnote no. 4</footnote>
        <footnote id="F4">continued from footnote no. 3; 1,700 @ $47.91; 400 @ $47.92; 3,300 @ $47.93; 400 @ $47.94; 400 @ $47.96; 400 @ $47.97; 400 @ $47.98; 2,300 @ $47.99; 800 @ $48; 300 @ $48.01; 400 @ $48.02; 600 @ $48.04; 600 @ $48.05; 400 @ $48.06; 400 @ $48.07; 500 @ $48.08; 700 @ $48.10; 400 @ $48.11; 1,000 @ $48.12; 1,300 @ $48.13; 500 @ $48.14; 1,000 @ $48.15; 453 @ $48.16; 500 @ $48.17; 400 @ $48.18; 1,500 @ $48.19; 500 @ $48.20; 500 @ $48.21; 500 @ $48.22; 300 @ $48.24; 147 @ $48.25; 200 @ $48.26; 2,100 @ $48.28; 1,100 @ $48.29; 300 @ $48.30; 1,100 @ $48.31; 1,300 @ $48.33; 1,100 @ $48.36; 1,000 @ $48.37; 100 @ $48.41; 200 @ $48.42; 1,100 @ $48.46; 1,600 @ $48.47; 200 @ $48.49; 2,400 @ $48.53; 1,200 @ $48.63; 200 @ $48.64; 100 @ $48.67; 200 @ $48.69; 900 @ $48.71 and 600 @ $48.86.</footnote>
        <footnote id="F5">Based upon units held in 401k Plan and the fair market value of Common Stock as of February 1, 2008.</footnote>
        <footnote id="F6">This option vested in three equal installments on March 6, 2002, 2003 and 2004.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Renee Hack, by power of attorney</signatureName>
        <signatureDate>2008-02-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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