Acute severe ulcerative colitis (ASUC) is a potentially life-threatening condition. In the present review, we give a broad overview of the state of the art in the management of this condition. A systematic bibliographic search was performed in PubMed. Patient with ASUC should be hospitalized and managed by a multidisciplinary team (gastroenterologist plus surgeon). Intravenous corticosteroids remain the cornerstone of medical therapy. However, about 30% of patients do not respond. After failing 3-5 days of corticosteroids, patients should be considered for either rescue medical therapy or for colectomy. Cyclosporin and infliximab are similarly effective and safe. Cyclosporin should be mainly used as a "bridge" in thiopurine-naïve patients. More recently, infliximab has become the most widely used salvage therapy. Third-line salvage therapy with either cyclosporin or infliximab is efficacious in some patients but carries a significant risk of complications. Colectomy is appropriate in case of complications or medical rescue therapy failure.