The role is reviewed of sulphasalazine, 5-aminosalicylic acid (5-ASA), immunosuppressive agents and corticosteroids in the maintenance treatment of ulcerative colitis in remission. Sulphasalazine and oral 5-ASA are the drugs of first choice in preventing relapses for patients suffering from intermittent chronic ulcerative colitis. Rectally administered 5-ASA may be a valid alternative for treating patients with proctitis and left-sided ulcerative colitis. The optimal dosage of oral 5-ASA in the maintenance therapy of ulcerative colitis in remission is not clear. However, there is evidence that a higher dose of 5-ASA is more effective than low dosage in preventing relapses in patients in remission. For patients with chronically active or steroid-dependent ulcerative colitis who have achieved remission while taking immunosuppressants, continuing azathioprine or 6-mercaptopurine is indicated. Existing data cast doubts as to whether or not continuous maintenance is still necessary in patients suffering from intermittent chronic ulcerative colitis with prolonged endoscopic, clinical and histological remission.