<ARTICLE>           5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THERMEDICS
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>                                                142,108
<SECURITIES>                                           43,310
<RECEIVABLES>                                          67,936
<ALLOWANCES>                                            4,498
<INVENTORY>                                            62,783
<CURRENT-ASSETS>                                      326,211
<PP&E>                                                 60,687
<DEPRECIATION>                                         38,780
<TOTAL-ASSETS>                                        553,618
<CURRENT-LIABILITIES>                                  93,919
<BONDS>                                               122,802
<PREFERRED-MANDATORY>                                       0
<PREFERRED>                                                 0
<COMMON>                                                4,174
<OTHER-SE>                                            243,802
<TOTAL-LIABILITY-AND-EQUITY>                          553,618
<SALES>                                               313,131
<TOTAL-REVENUES>                                      313,131
<CGS>                                                 164,345
<TOTAL-COSTS>                                         164,345
<OTHER-EXPENSES>                                       26,595
<LOSS-PROVISION>                                        1,002
<INTEREST-EXPENSE>                                      5,581
<INCOME-PRETAX>                                        40,058
<INCOME-TAX>                                           15,312
<INCOME-CONTINUING>                                    18,972
<DISCONTINUED>                                              0
<EXTRAORDINARY>                                         4,638
<CHANGES>                                                   0
<NET-INCOME>                                           23,610
<EPS-PRIMARY>                                            0.57
<EPS-DILUTED>                                            0.55