<ARTICLE>                                     5
<LEGEND>

                                    CASTELLE
                             FINANCIAL DATA SCHEDULE


This  schedule  contains  summary  financial   information  extracted  from  the
Company's  Financial  Statements for the nine month period ending  September 26,
1997  included  in the  Company's  Form  10-Q  filed  November  10,  1997 and is
qualified in its entirety by reference to such statements
</LEGEND>
<MULTIPLIER>                                  1,000
       
                                                     
<PERIOD-TYPE>                                 9-MOS
<FISCAL-YEAR-END>                             DEC-31-1997
<PERIOD-END>                                  SEP-26-1997

<CASH>                                                                   6,760
<SECURITIES>                                                                 0
<RECEIVABLES>                                                            6,347
<ALLOWANCES>                                                               484
<INVENTORY>                                                              3,597
<CURRENT-ASSETS>                                                        18,451
<PP&E>                                                                   4,372
<DEPRECIATION>                                                           3,390
<TOTAL-ASSETS>                                                          22,381
<CURRENT-LIABILITIES>                                                    6,590
<BONDS>                                                                      0
<PREFERRED-MANDATORY>                                                        0
<PREFERRED>                                                                  0
<COMMON>                                                                23,819
<OTHER-SE>                                                                   0
<TOTAL-LIABILITY-AND-EQUITY>                                            22,381
<SALES>                                                                 23,756
<TOTAL-REVENUES>                                                        20,018

<CGS>                                                                    9,192
<TOTAL-COSTS>                                                            9,192
<OTHER-EXPENSES>                                                        11,738
<LOSS-PROVISION>                                                             0
<INTEREST-EXPENSE>                                                           0
<INCOME-PRETAX>                                                          (755)
<INCOME-TAX>                                                               294
<INCOME-CONTINUING>                                                    (1,049)
<DISCONTINUED>                                                               0
<EXTRAORDINARY>                                                              0
<CHANGES>                                                                    0
<NET-INCOME>                                                           (1,049)
<EPS-PRIMARY>                                                           (0.24)
<EPS-DILUTED>                                                           (0.24)