Nineteen patients with asthma completed an open, randomized, crossover study in which 0.5 mg terbutaline sulphate was administered either via Turbuhaler or via the metered dose inhaler (MDI) for 2-week periods. The clinical effect of the two treatment forms was comparable; both provided adequate bronchodilator therapy. Patients also considered Turbuhaler and MDI equally effective, with a small preference for the MDI. Turbuhaler seems to be a valuable alternative to bronchodilator MDI therapy.