<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED CONDENSED FINANCIAL STATEMENTS OF AMERICAN SCIENCE AND ENGINEERING,
INC. FOR THE YEAR ENDED MARCH 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000
<CURRENCY> US$

                             
<PERIOD-TYPE>                   12-MOS
<FISCAL-YEAR-END>                          MAR-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               MAR-31-1999
<EXCHANGE-RATE>                                      1
<CASH>                                             366
<SECURITIES>                                         0
<RECEIVABLES>                                    7,958
<ALLOWANCES>                                         0
<INVENTORY>                                     11,083
<CURRENT-ASSETS>                                24,375
<PP&E>                                           5,042
<DEPRECIATION>                                   9,677
<TOTAL-ASSETS>                                  30,204
<CURRENT-LIABILITIES>                           10,329
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         3,252
<OTHER-SE>                                      16,095
<TOTAL-LIABILITY-AND-EQUITY>                    30,204
<SALES>                                         57,295
<TOTAL-REVENUES>                                57,295
<CGS>                                           38,356
<TOTAL-COSTS>                                   53,819
<OTHER-EXPENSES>                                  (67)
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                  3,409
<INCOME-TAX>                                     1,364
<INCOME-CONTINUING>                              2,045
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     2,045
<EPS-BASIC>                                       0.43
<EPS-DILUTED>                                     0.40