Oxaprozin is a newer non-steroidal anti-inflammatory drug advocated for use in painful rheumatic and inflammatory conditions. As is the case with some other newer non-steroidal anti-inflammatory drugs, oxaprozin offers the convenience of once-daily administration. Published data suggest that oxaprozin 1200 mg once daily is comparable in effectiveness with usual dosages of aspirin, ibuprofen, indomethacin, naproxen, piroxicam and sulindac in the treatment of rheumatoid arthritis and osteoarthritis. More controlled clinical trials in adequate numbers of patients are necessary to evaluate its potential in other rheumatic and inflammatory conditions. Oxaprozin produced fewer gastrointestinal side effects than aspirin, and the short term tolerability of oxaprozin was similar to that of other non-steroidal anti-inflammatory drugs. If further definition of its efficacy and tolerability compared with other non-steroidal anti-inflammatory drugs during long term therapy confirms these initially favourable results, then oxaprozin would appear to offer a useful and convenient alternative in the treatment of painful rheumatic and inflammatory conditions.