The compliance of 114 patients with chronic airways disease to therapy with aerosol salbutamol and beclomethasone dipropionate was examined over two consecutive periods of approximately four weeks. Values ranging from 90-110 percent compliance were recorded for the two agents and a further increase in compliance was noted with both aerosols during the second month of surveillance. Over-use of salbutamol occurred in those patients who had been recently discharged from hospital. It was concluded that the high level of compliance was due to the symptomatic nature of the illness and the over-use of the bronchodilator was attributed to the usually prompt relief it provided.