<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THERMO INSTRUMENT SYSTEMS INC.'S QUARTERLY REPORT ON FORM 10-Q FOR THE PERIOD ENDED APRIL 4, 1998 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <MULTIPLIER> 1,000 <PERIOD-TYPE> 3-MOS <FISCAL-YEAR-END> JAN-02-1999 <PERIOD-END> APR-04-1998 <CASH> 678,595 <SECURITIES> 8,496 <RECEIVABLES> 369,448 <ALLOWANCES> 22,675 <INVENTORY> 274,597 <CURRENT-ASSETS> 1,397,480 <PP&E> 318,302 <DEPRECIATION> 104,923 <TOTAL-ASSETS> 2,550,295 <CURRENT-LIABILITIES> 569,596 <BONDS> 612,590 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 12,277 <OTHER-SE> 889,780 <TOTAL-LIABILITY-AND-EQUITY> 2,550,295 <SALES> 407,943 <TOTAL-REVENUES> 407,943 <CGS> 214,209 <TOTAL-COSTS> 214,209 <OTHER-EXPENSES> 28,519 <LOSS-PROVISION> 185 <INTEREST-EXPENSE> 11,493 <INCOME-PRETAX> 64,114 <INCOME-TAX> 21,959 <INCOME-CONTINUING> 37,855 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 37,855 <EPS-PRIMARY> .31 <EPS-DILUTED> .28