Forty-five steroid-dependent asthmatic outpatients were treated twice daily for 51 weeks with a new inhalation steroid, budesonide (BUD), using a 750 ml spacer. During the initial 15 weeks the prednisone-sparing effects of a high daily dose (1600 micrograms) and a conventional dose (400 micrograms per day) were compared in a double-blind randomized trial including 50 patients. During the remaining 36 weeks 45 patients were treated openly with 1600 micrograms daily. All patients used other antiasthmatic drugs which were maintained throughout the study, except for inhalations of beta-2 agonists that could be used whenever needed. All patients but 2 were able to reduce the daily dose of oral prednisone. The mean daily dose decreased from 13.9 mg to 5.3 mg. Eighteen patients (40%) were able to discontinue oral prednisone. Adrenal gland function improved considerably as prednisone intake decreased. Oropharyngeal thrush frequency showed no change. No severe side effects were observed.