<ARTICLE> 5
<CIK> 0000932064
<NAME> SECURITY DYNAMICS TECHNOLOGIES, INC.
<MULTIPLIER> 1,000
<CURRENCY> U.S. DOLLARS
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               MAR-31-1997
<EXCHANGE-RATE>                                      1
<CASH>                                          14,310
<SECURITIES>                                    89,208
<RECEIVABLES>                                   14,139
<ALLOWANCES>                                       546
<INVENTORY>                                      2,798
<CURRENT-ASSETS>                               125,573
<PP&E>                                          14,515
<DEPRECIATION>                                   3,981
<TOTAL-ASSETS>                                 140,577
<CURRENT-LIABILITIES>                           12,744
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           350
<OTHER-SE>                                     125,797
<TOTAL-LIABILITY-AND-EQUITY>                   140,577
<SALES>                                         26,436
<TOTAL-REVENUES>                                26,436
<CGS>                                            6,041
<TOTAL-COSTS>                                   20,138
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                    30
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                  7,571
<INCOME-TAX>                                     2,842
<INCOME-CONTINUING>                              4,729
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     4,729
<EPS-PRIMARY>                                     0.13
<EPS-DILUTED>                                     0.13
<FN>
INCOME-PRETAX INCLUDES $1,273 INTEREST & OTHER INCOME
TOTAL-LIABILITY-AND-EQUITY INCLUDES $1,686 MINORITY INTEREST.