We report the case of a 41-year-old woman with a 5-year history of left-sided ulcerative colitis easily controlled by sulfasalazine. She was admitted because of severe anemia, in the absence of any exacerbation of the colitis. A Coombs-positive (IgG type) hemolytic anemia was diagnosed and high-dose corticosteroid therapy was started, which proved to be unsuccessful. A splenectomy was then performed but the hemolytic anemia failed to subside. The patient was subsequently treated with a corticosteroid-azathioprine association with a sustained favourable effect on the anemia. The prevalence and pathophysiology of hemolytic anemia in ulcerative colitis is reviewed and a specific therapeutic approach is proposed.