Thirty-eight patients with chronic asthma requiring continuous oral corticosteroid treatment took part in a 2-year study. Budesonide, a new inhalation steroid with high topical activity and low systemic effects, was given in stepwise increasing doses from 200 micrograms daily up to 800-1600 micrograms daily and prednisolone doses were decreased gradually on an individual basis. After 2 years, 18 patients had been able to cease oral prednisolone treatment, 11 had decreased the dose by greater than or equal to 50%, three by less than or equal to 50% and two patients had increased their dose. At the end of the study the majority of patients (26) were using 800 micrograms budesonide daily and seven, 1200 micrograms or more daily. There were two dropouts, one due to local side effects and one to a severe pulmonary eosinophilia. Ten patients had local side effects in the form of hoarseness and/or sore throat, and 13 patients had steroid withdrawal symptoms such as arthralgia and myalgia. The asthma condition in all patients was improved, as indicated by the reduced need for hospital admissions. The results indicate that high doses of budesonide should be tried before starting maintenance therapy with oral steroids.