Aim. To assess the long-term result of medical treatment in patients with a severe attack (SA) of ulcerative colitis (UC). Subjects and methods. The course of UC was analyzed in 56 patients who were accessible by telephone contact and consecutively recruited for a year after therapy for a SA of UC. All the patients were stated to have a SA of UC according to the Truelove-Witts’ criteria; they received therapy with intravenous glucocorticosteroids (GCS) (prednisolone 2 mg/kg) along with anti-recurrence therapy with mesalasine (5-ASA) or azathioprine (AZA). Ten (17.9%) GCS-resistant patients were given infliximab (INF) (5 mg/kg), followed by its maintenance infusions. Anti-recurrence therapy using 5-ASA, AZA, and INF was performed in 33 (58.9%), 13 (23.2%), and 10 (17.9%) patients, respectively. Results. During one year, 14 (25%) patients continued to be in clinical remission on maintenance therapy or to have attacks stopped without using GCS, immunosuppressive agents, or INF (a satisfactory response group). Colectomy was carried out in 23 (41.1%) patients; due to recurrent UC when decreasing the dose of GCS, 5 (8.9%) patients continued to take the latter during a year. A GCS cycle was repeated in 3 patients who had received AZA (the basic therapy was not corrected) and 11 patients who had taken 5-ASA. The prognostic factors for a long-term result of medical therapy included the choice of AZA as an anti-recurrent drug (57.1 and 11.9% in the satisfactory and poor treatment outcome groups, respectively; p=0.004) and patient age (34.4 and 42.8 years, respectively; p=0.0357). Conclusion. During 1 year after a SA of UC, indications for colectomy and repeated GCS use occurred in 41 and 34% of the patients, respectively. The long-term efficiency of medical therapy for a SA of UC declines with advancing age. The use of AZA as an anti-recurrence agent after termination of GCS intake increases the probability of long-term clinical response.