AIM To elaborate optimal cell culture administration regimens to enhance the efficiency of anti-inflammatory therapy for inflammatory bowel diseases. SUBJECTS AND METHODS Three groups of patients with chronic continuous or chronic recurrent ulcerative colitis (UC) were formed according to the treatment option: 1) 15 patients with UC, in whom mesenchymal stromal cells (MSC) were thrice administered for a month at a one-week interval; 2) 20 patients with UC who received MSC once; 3) 20 patients with UC who had standard anti-inflammatory therapy with 5-aminosalycilic acid (5-ASA) preparations and glucocorticosteroids (GCS). The clinical activity of UC was evaluated using the Rachmilewitz index; its endoscopic pattern was assessed with the Mayo index. UC histological specimens were scored using the Gebs scale. To ascertain the duration of remission, the authors used the Kaplan-Maier survival curve method and calculated relative risk (RR) and odds ratio with 95% confidence intervals. RESULTS Following 12 months, allogeneic bone marrow (BM) MSC transplantation performed thrice during a month caused the greatest reduction in the Rachmilewitz clinical activity index, Mayo endoscopic activity index, and Gebs pathohistological index in patients with UC as compared to those who had underwent one transplantation or received 5-ASA preparations and GCS (p < 0.05). The duration of remission also depended on the chosen therapy option for UC and the frequency of cell culture administration: the longer duration was recorded in patients who were infused thrice with allogeneic BM MSC. CONCLUSION In the patients who had undergone one MSC administration, the risk of recurrent UC was higher than in those who had received MSC thrice during a month (a 2-year follow-up) and comparable with the RR of recurrent UC in the patient receiving only 5-ASA preparations, GCS, and/or immunosuppressants.