<ARTICLE>           5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM
THERMEDICS INC.'S
ANNUAL REPORT ON FORM 10-K FOR THE PERIOD 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>                                                 81,950
<SECURITIES>                                                0
<RECEIVABLES>                                          47,733
<ALLOWANCES>                                            2,850
<INVENTORY>                                            40,958
<CURRENT-ASSETS>                                      254,438
<PP&E>                                                 33,838
<DEPRECIATION>                                         22,484
<TOTAL-ASSETS>                                        408,483
<CURRENT-LIABILITIES>                                  70,606
<BONDS>                                                47,552
<PREFERRED-MANDATORY>                                       0
<PREFERRED>                                                 0
<COMMON>                                                4,174
<OTHER-SE>                                            243,953
<TOTAL-LIABILITY-AND-EQUITY>                          408,483
<SALES>                                               208,644
<TOTAL-REVENUES>                                      208,644
<CGS>                                                 114,222
<TOTAL-COSTS>                                         114,222
<OTHER-EXPENSES>                                       12,902
<LOSS-PROVISION>                                          610
<INTEREST-EXPENSE>                                      1,777
<INCOME-PRETAX>                                        28,292
<INCOME-TAX>                                           10,688
<INCOME-CONTINUING>                                    14,939
<DISCONTINUED>                                          4,074
<EXTRAORDINARY>                                         4,597
<CHANGES>                                                   0
<NET-INCOME>                                           23,610
<EPS-BASIC>                                            0.57
<EPS-DILUTED>                                            0.55