AIM: The 60% bioavailable oral microemulsion formulation of cyclosporin (NEORAL ), has replaced the intravenous route to treat both organ transplant and immune-based disease. Its use for steroid-refractory ulcerative colitis (a recognized indication for intravenous cyclosporin) has been scanty. METHODS: Twenty-three consecutive patients (14 male/9 female, universal colitis 14/23) entered a 3-month course of NEORAL (initially dosed at 5 mg/kg/day) because of steroid-refractoriness (14 cases) and steroid-dependence (9 cases). Responders (at least showing a 50% reduction of a clinical activity score) were continued on azathioprine. The initial steroid dose was tapered on commencing NEORAL; patients requiring steroid resumption or increase in the follow-up were defined as relapsers. RESULTS: The target trough concentration of 200 ng/ml of whole blood was achieved without major titration in all but 1 patient. There were 7 non-responders (30%). Of the 16 responders (70%), 2 have not relapsed; the remaining 14 relapsed at the median time of 9.5 months (1.5-60) with 10 (71%) showing only 1 relapse. Five patients were colectomized 12 months after NEORAL (1.5-24), leaving 11 of the initial 23 (47%) with their colon. Of the 16, all but 1 had azathioprine; the median daily steroid needs fell from 32 to 5 mg. CONCLUSION: The rates of acute and chronic response of 70% and 47% achieved by NEORAL in this indication duplicate the figures achieved by the traditional schedules of cyclosporin administration.