One hundred male patients who presented with acute gouty arthritis were alternately assigned to 2 treatment groups. Seventy-six patients completed the study protocol, in which each gout attack during a 1-year period was treated. For each gout episode, 36 patients received a single intramuscular injection of 40 IU of adrenocorticotropic hormone (ACTH), and 40 patients received oral indomethacin, 50 mg 4 times daily with meals, until the pain abated. The time interval until the pain was relieved, as well as any untoward effects, were recorded for each gout attack treated. Both groups were of similar age, and had similar values for intercritical serum uric acid, 24-hour urinary uric acid, and creatinine clearance (1 month after entry into the study). The mean interval (+/- SD) to relief of pain was significantly shorter for the ACTH group (3 +/- 1 hours) than for the indomethacin group (24 +/- 10 hours). No side effects were noted in the ACTH group. However, of the 40 patients receiving indomethacin, 22 had abdominal discomfort of dyspepsia, 15 had headaches, and 12 had difficulty with mentation. Single-dose parenteral ACTH appeared to be effective more rapidly and was associated with fewer side effects than oral indomethacin in the treatment of acute gout.