<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM
ARIBA INC'S QUARTERLY REPORT ON FORM 10-Q FOR THE PERIOD ENDED JUNE 30, 1999
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          SEP-30-1999
<PERIOD-START>                             OCT-01-1998
<PERIOD-END>                               JUN-30-1999
<CASH>                                         144,669
<SECURITIES>                                     6,799
<RECEIVABLES>                                    5,976
<ALLOWANCES>                                      (20)
<INVENTORY>                                          0
<CURRENT-ASSETS>                               158,081
<PP&E>                                           6,801
<DEPRECIATION>                                   1,681
<TOTAL-ASSETS>                                 163,486
<CURRENT-LIABILITIES>                           35,779
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                            91
<OTHER-SE>                                     126,924
<TOTAL-LIABILITY-AND-EQUITY>                   163,486
<SALES>                                         16,939
<TOTAL-REVENUES>                                28,231
<CGS>                                              581
<TOTAL-COSTS>                                    5,203
<OTHER-EXPENSES>                                42,833
<LOSS-PROVISION>                                    20
<INTEREST-EXPENSE>                                  95
<INCOME-PRETAX>                               (19,421)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                           (19,421)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                  (19,421)
<EPS-BASIC>                                     (1.79)
<EPS-DILUTED>                                   (1.79)