Two hundred four courses of intensive intravenous treatment were given to 158 patients with ulcerative colitis. The remission rates in the severe, moderate, or mild attacks were 55.7%, 86.9%, and 91.8%. Total colitis had a great impact on the results, especially in severe attacks. Of these patients, 52.8% were operated on within 3 wk. The relapse rate was exponential, and during the first year 48.1% of the patients in remission relapsed. The extent of the colitis, severity of the attack, or duration of intensive intravenous treatment had no influence on the time of relapse. Twelve patients with chronic continuous disease were given intensive intravenous treatment. No long-term benefit was seen in patients with total ulcerative colitis, but half of those with less extensive colitis showed a good to excellent response to treatment.