Ulcerative colitis (UC) is a chronic inflammatory bowel disease that slightly reduces life expectancy, strongly reduces its quality and can lead to serious complications such as acute colitis, dysplasia and colon cancer. About 40'000 patients are affected in France Among them, 15% suffer from a chronic active form that often leads to an extended steroid therapy, and its known side effects. Azathioprine has already proven its efficacy in this indication but brings a lasting remission without steroid in only 41% of the patients (1-4). What are the medications available for the patients who failed in maintaining a remission with azathioprine ? Cyclosporin is designed for severe or steroid-resistant forms. (5). The results of two recent studies have showed that infliximab is more efficacious than placebo in active UC (6, 7). Infliximab is expensive, its efficacy in steroid-dependent UC has not been specifically tested yet, and its tolerance on the long term remains uncertain. Methotrexate proved its efficacy in Crohn's disease with an intramuscular dose of 25mg/week (8). In UC a controlled trial has been negative with an oral dose of 12.5mg/week (9). Another study compared mercaptopurine, methotrexate (15mg/week) and 5-aminosalicylate in 72 steroid-dependent patients with CD or UC (10). The remission rates obtained were 58% after 30 weeks with methotrexate (not significantly different from 5-ASA) and 14% after 106 weeks (not significantly different from 5-ASA). Few data are available on the efficacy of methotrexate in UC, at a dose which is active in Crohn's disease (25mg intramuscular/week). Several uncontrolled series have been published, including 91 patients whose remission failed under azathioprine.