A six-month double-blind controlled trial compared a 2,000 microgram per day dose of beclomethasone dipropionate aerosol (BDP), with current upper level doses of 800 micrograms per day of the standard BDP, in asthmatics requiring oral corticosteroids in addition to BDP and bronchodilators. Both groups showed a significant reduction in their oral steroid requirements during the study, with a 34 percent reduction in the lower dose group and a 57 percent reduction in the high dose BDP group while maintaining good symptomatic control of asthma; there was an associated improvement in baseline serum cortisol levels. Over the same period, the pulmonary function of the lower dose group showed significant worsening relative to that of the group receiving the high dose BDP which improved. There was no increase in dysphonia or oropharyngeal candidiasis among those using the concentrated BDP. We conclude that high dose concentrated BDP appears to be a safe medication in long-term steroid-dependent asthma, and is effective in reducing dependence on the use of oral corticosteroid with associated improvement both in pulmonary and adrenal function.