One hundred and five patients with a diagnosis of early nonerosive rheumatoid arthritis (RA) were randomized to receive enteric coated sulfasalazine as Salazopyrin En-tabs or placebo for 6 months. Sixty-five patients completed this 6 month treatment period. Patients taking sulfasalazine were significantly better than those taking placebo in terms of Ritchie articular index, number of swollen and tender joints and erythrocyte sedimentation rate. The sulfasalazine group also demonstrated a significant fall in serum hyaluronic acid, IgM rheumatoid factor and C-reactive protein concentration. Side effects leading to withdrawal from treatment occurred in 14 of the sulfasalazine group and 4 of the placebo group. The most common side effects of patients taking sulfasalazine were rashes, liver function test abnormalities and gastrointestinal upsets. Our study demonstrates the efficacy of sulfasalazine in early RA.