<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM MCDERMOTT
INTERNATIONAL'S SEPTEMBER 30, 1998 FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          MAR-31-1999
<PERIOD-END>                               SEP-30-1998
<CASH>                                         345,934
<SECURITIES>                                       326
<RECEIVABLES>                                  545,521
<ALLOWANCES>                                    67,233
<INVENTORY>                                    256,756
<CURRENT-ASSETS>                             1,394,562
<PP&E>                                       1,509,352
<DEPRECIATION>                               1,039,874
<TOTAL-ASSETS>                               3,892,955
<CURRENT-LIABILITIES>                        1,220,381
<BONDS>                                        567,948
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        60,910
<OTHER-SE>                                     761,869
<TOTAL-LIABILITY-AND-EQUITY>                 3,892,955
<SALES>                                      1,599,792
<TOTAL-REVENUES>                             1,599,792
<CGS>                                        1,470,194
<TOTAL-COSTS>                                1,470,194
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              32,236
<INCOME-PRETAX>                                196,099
<INCOME-TAX>                                    22,923
<INCOME-CONTINUING>                            173,176
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   173,176
<EPS-PRIMARY>                                     2.92
<EPS-DILUTED>                                     2.76