Beclomethasone dipropionate (BDP) was used in a trial to assess the effectiveness of twice daily compared with four times daily dosage in the control of asthma. Prior to the introduction of BDP all but one of the patients were dependent on oral steroids in addition to other therapeutic regimes for adequate control of their asthma. A cross-over design was used with patients randomly allocated to either a twice daily or four times daily initial BDP regime. The trial continued for thirty-two weeks, with patients changing their dose regime at the end of each eight week period. Maintenance steroids were eliminated in all but two of the patients. According to all the criteria used in assessing control of asthma, there were no significant differences between the two regimes, indicating that both were equally effective. Compliance was better with the twice daily regime, and most patients preferred it.