The present results call into question the routine use of a high (i.e., antiinflammatory) dose of ibuprofen for osteoarthritis of the knee. It should be emphasized that our study evaluated only short-term treatment of this condition. Possibly, the long-term outcome of treatment of the knee, the outcome of treatment of other joints, or the outcome in patients with osteoarthritis characterized by greater inflammation than in our patients would differ from the outcome reported here. However, the knee is one of the joints most commonly affected by osteoarthritis and the chief source of disability in this disease, and the importance of successful treatment of such osteoarthritis cannot be argued.