<ARTICLE>                     5
<LEGEND>
This  schedule  contains  summary  financial   information  extracted  from  the
Bioanalytical  Systems, Inc. consolidated  financial statements contained in the
company's  annual  report  on Form  10-K and is  qualified  in its  entirety  by
reference to such financial statements.
</LEGEND>
<MULTIPLIER>  1000
       
                                                              
<PERIOD-TYPE>                                      3-MOS                  6-MOS
<FISCAL-YEAR-END>                            SEP-30-1999            SEP-30-1999
<PERIOD-START>                               JAN-01-1999            OCT-01-1998
<PERIOD-END>                                 MAR-31-1999            MAR-31-1999
<CASH>                                               854                    854
<SECURITIES>                                           0                      0
<RECEIVABLES>                                      3,223                  3,223
<ALLOWANCES>                                           0                      0
<INVENTORY>                                        1,927                  1,927
<CURRENT-ASSETS>                                   6,289                  6,289
<PP&E>                                            20,815                 20,815
<DEPRECIATION>                                     4,464                  4,464
<TOTAL-ASSETS>                                    23,950                 23,950
<CURRENT-LIABILITIES>                              4,555                  4,555
<BONDS>                                                0                      0
<PREFERRED-MANDATORY>                                  0                      0
<PREFERRED>                                            0                      0
<COMMON>                                             999                    999
<OTHER-SE>                                        16,042                 16,042
<TOTAL-LIABILITY-AND-EQUITY>                      23,950                 23,950
<SALES>                                            2,329                  4,624
<TOTAL-REVENUES>                                   5,057                  9,655
<CGS>                                                876                  1,823
<TOTAL-COSTS>                                      2,520                  5,022
<OTHER-EXPENSES>                                   2,197                  4,275
<LOSS-PROVISION>                                       0                      0
<INTEREST-EXPENSE>                                    24                     65    
<INCOME-PRETAX>                                      354                    344
<INCOME-TAX>                                         154                    150
<INCOME-CONTINUING>                                  200                    194
<DISCONTINUED>                                         0                      0
<EXTRAORDINARY>                                        0                      0
<CHANGES>                                              0                      0    
<NET-INCOME>                                         200                    194
<EPS-PRIMARY>                                        .04                    .04
<EPS-DILUTED>                                        .04                    .04