A randomized, double-blind, double-dummy crossover study on 42 asthmatics was carried out to compare the single dose effects of salbutamol administered from the widely used metered dose inhaler and a breath operated system (Diskhaler). The bronchodilator response (change in forced expiratory volume in the first second) was almost identical for the two systems. The Diskhaler system however, since it is breath operated, obviates the need for hand-breath coordination.