The anti-inflammatory activity of the stem extracts of Sandoricum koetjape was investigated on topical administration using the TPA (tetradecanoylphorbol acetate)-induced mouse ear inflammation model. Bioassay-guided chromatographic fractionation of active fractions led to the isolation 3-oxo-12-oleanen-29-oic acid and katonic acid as the bioactive principles responsible for the anti-inflammatory acitivity. The percentage of inhibition exhibited by 3-oxo-12-oleanen-29-oic acid was almost equivalent to indomethacin.