-----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,
 V1wvQ5wjm48YAsIUnLCUuMuFvmQGOR9+qIH3mRK/p4Nftji+RbIy4YXxwILXi6rA
 KppF/0y+iAbygQ7q4QgrxQ==

<SEC-DOCUMENT>0001241921-08-000025.txt : 20080404
<SEC-HEADER>0001241921-08-000025.hdr.sgml : 20080404
<ACCEPTANCE-DATETIME>20080404163034
ACCESSION NUMBER:		0001241921-08-000025
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080402
FILED AS OF DATE:		20080404
DATE AS OF CHANGE:		20080404

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:		08740829

	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>2008-04-02</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>2008-04-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>29962</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>57.89</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>685832</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-04-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>43640</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.845</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>729472</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-04-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>43640</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>685832</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>10297</value>
                    <footnoteId id="F4"/>
                </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>2008-04-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>43640</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2011-03-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>43640</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>114460</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 3, 2008.</footnote>
        <footnote id="F2">The stock was sold in multiple transactions at the following prices: 200 @ $56.81; 600 @ $56.82; 200 @ $56.86; 100 @ $56.87; 500 @ $56.89; 240 @ $56.90; 200 @ $56.91; 100 @ $56.92; 200 @ $57.01; 312 @ $57.03; 200 @ $57.06; 1,688 @ $57.12; 200 @ $57.15; 600 @ $57.20; 400 @ $57.23; 200 @ $57.24; 200 @ $57.27; 400 @ $57.30; 1,000 @ $57.33; 200 @ $57.35; 1,500 @ $57.36; 200 @ $57.39; 200 @ $57.40; 200 @ $57.41; 200 @ $57.42; 600 @ $57.44; 400 @ $57.45; 700 @ $57.46; 1,400 @ $57.49; 400 @ $57.51; 100 @ $57.52; 500 @ $57.54; 100 @ $57.56; 300 @ $57.57; 1,000 @ $57.59; 800 @ $57.60; 200 @ $57.61; 1,224 @ $57.63; 876 @ $57.64; 600 @ $57.67; 100 @ $57.70; 1,500 @ $57.73; 2,500 @ $57.74; 478 @ $57.75; 200 @ $57.76; 322 @ $57.80; 200 @ $57.81; 100 @ $57.82; 300 @ $57.83; 200 @ $57.84; 900 @ $57.85; 200 @ $57.86; 600 @ $57.87; 300 @ $57.88; 700 @ $57.89; 300 @ $57.91; continued on footnote no. 3</footnote>
        <footnote id="F3">continued from footnote no. 2; 400 @ $57.93; 200 @ $57.96; 300 @ $57.97; 200 @ $57.98; 600 @ $57.99; 200 @ $58.00; 400 @ $58.02; 400 @ $58.04; 200 @ $58.06; 600 @ $58.08; 600 @ $58.09; 800 @ $58.10; 500 @ $58.11; 300 @ $58.12; 2,200 @ $58.13; 600 @ $58.14; 500 @ $58.15; 500 @ $58.16; 600 @ $58.17; 500 @ $58.19; 800 @ $58.20; 500 @ $58.22; 200 @ $58.23; 400 @ $58.24; 100 @ $58.25; 2,000 @ $58.26; 300 @ $58.30; 400 @ $58.32 and 200 @ $58.35.</footnote>
        <footnote id="F4">Based upon units held in 401k Plan and the fair market value of Common Stock as of April 1, 2008.</footnote>
        <footnote id="F5">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>2008-04-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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