Nimesulide is a new non-steroidal anti-inflammatory drug (NSAID). In this paper, its antiinflammatory, analgesic and antipyretic effects in mice rat or rabbit were evaluated. Nimesulide inhibited the ear oedema induced by croton oil in mice (ED50=49. 2 mg ? kg-1). It inhibitated rat hind paw oedema induced by carragreenin (ED50= 2.75 mg ? kg-1). Oral dose (0. 6 mg ? kg-1) showed sup-pressive effect on adjuvant arthritis in rat. Oraldose (100 mg ? kg-1) decreased writhing induced by acetic acid. Similar effect was observed in hot plate test on mice. Nimesulide (2 mg ? kg-1) decreased body tempreture elevated by injecting peptone in rabbit (P