<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 3, 1998
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER>        1,000

                              
<PERIOD-TYPE>                                 YEAR
<FISCAL-YEAR-END>                             JAN-03-1998
<PERIOD-END>                                  JAN-03-1998
<CASH>                                                101,246
<SECURITIES>                                            9,687
<RECEIVABLES>                                          42,297
<ALLOWANCES>                                            2,574
<INVENTORY>                                            33,873
<CURRENT-ASSETS>                                      262,364
<PP&E>                                                 27,808
<DEPRECIATION>                                         18,960
<TOTAL-ASSETS>                                        380,179
<CURRENT-LIABILITIES>                                  48,498
<BONDS>                                                65,021
<PREFERRED-MANDATORY>                                       0
<PREFERRED>                                                 0
<COMMON>                                                3,685
<OTHER-SE>                                            224,166
<TOTAL-LIABILITY-AND-EQUITY>                          380,179
<SALES>                                               200,184
<TOTAL-REVENUES>                                      200,184
<CGS>                                                 103,677
<TOTAL-COSTS>                                         103,677
<OTHER-EXPENSES>                                       11,968
<LOSS-PROVISION>                                          369
<INTEREST-EXPENSE>                                        597
<INCOME-PRETAX>                                        53,825
<INCOME-TAX>                                           13,781
<INCOME-CONTINUING>                                    36,861
<DISCONTINUED>                                          4,631
<EXTRAORDINARY>                                             0
<CHANGES>                                                   0
<NET-INCOME>                                           41,492
<EPS-BASIC>                                            1.13
<EPS-DILUTED>                                            1.07