<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONATAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THERMEDICS
INC.'S ANNUAL REPORT ON FORM 10-K FOR THE YEAR ENDED JANUARY 3, 1998 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          JAN-03-1998
<PERIOD-END>                               JAN-03-1998
<CASH>                                         187,012
<SECURITIES>                                    58,317
<RECEIVABLES>                                   65,695
<ALLOWANCES>                                     4,207
<INVENTORY>                                     59,574
<CURRENT-ASSETS>                               379,160
<PP&E>                                          55,597
<DEPRECIATION>                                  33,986
<TOTAL-ASSETS>                                 536,552
<CURRENT-LIABILITIES>                           69,797
<BONDS>                                        142,771
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         3,685
<OTHER-SE>                                     223,661
<TOTAL-LIABILITY-AND-EQUITY>                   536,552
<SALES>                                        307,666
<TOTAL-REVENUES>                               307,666
<CGS>                                          155,680
<TOTAL-COSTS>                                  155,680
<OTHER-EXPENSES>                                24,270
<LOSS-PROVISION>                                   815
<INTEREST-EXPENSE>                               3,398
<INCOME-PRETAX>                                 68,897
<INCOME-TAX>                                    19,675
<INCOME-CONTINUING>                             41,492
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    41,492
<EPS-PRIMARY>                                     1.13
<EPS-DILUTED>                                     1.07