<ARTICLE>           5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THERMO
INSTRUMENT SYSTEMS INC.'S ANNUAL REPORT ON FORM 10-K FOR THE YEAR ENDED JANUARY
2, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER>        1,000
       
                              
<PERIOD-TYPE>                                 YEAR
<FISCAL-YEAR-END>                             JAN-02-1999
<PERIOD-END>                                  JAN-02-1999
<CASH>                                                553,825
<SECURITIES>                                                0
<RECEIVABLES>                                         431,156
<ALLOWANCES>                                           23,726
<INVENTORY>                                           276,589
<CURRENT-ASSETS>                                    1,333,584
<PP&E>                                                344,368
<DEPRECIATION>                                        124,137
<TOTAL-ASSETS>                                      2,565,774
<CURRENT-LIABILITIES>                                 587,629
<BONDS>                                               599,643
<PREFERRED-MANDATORY>                                       0
<PREFERRED>                                                 0
<COMMON>                                               12,288
<OTHER-SE>                                            932,719
<TOTAL-LIABILITY-AND-EQUITY>                        2,565,774
<SALES>                                             1,659,981
<TOTAL-REVENUES>                                    1,659,981
<CGS>                                                 889,575
<TOTAL-COSTS>                                         889,575
<OTHER-EXPENSES>                                      137,126
<LOSS-PROVISION>                                        4,169
<INTEREST-EXPENSE>                                     45,458
<INCOME-PRETAX>                                       193,916
<INCOME-TAX>                                           74,674
<INCOME-CONTINUING>                                   103,565
<DISCONTINUED>                                              0
<EXTRAORDINARY>                                           519
<CHANGES>                                                   0
<NET-INCOME>                                          104,084
<EPS-PRIMARY>                                            0.86
<EPS-DILUTED>                                            0.79