Budesonide is a topical steroid which after intestinal absorption is rapidly degraded into inactive metabolites in the liver. Its systemic bioavailability is only 10-15%. In the present open trial the efficiency and safety of oral pH-modified release budesonide were assessed in patients with active Crohn's ileocolitis. This report describes the results of the first 30 of 78 patients. After 6 weeks of treatment with 3 x 3 mg budesonide/day 67% of the patients were in clinical remission. Typical steroid-related side effects were observed in only one patient. Budesonide therefore seems to be suited as an alternative for classical steroids in patients with Crohn's ileocolitis. Its clinical efficacy is comparable with classical steroids but it's rate of steroid-related side effects is lower.