We investigated the antitussive effect of fenoterol in 40 patients (34 males) undergoing bronchofiberscopy for diagnostic purposes. The patients were randomly allocated into two groups, one receiving two puffs (400 micrograms) of fenoterol and the other two puffs of placebo, from a metered-dose inhaler in a double-blind fashion. The following procedure was used: premedication with 0.5 mg atropine sulfate and 100 mg hydroxyzine administered intramuscularly; 50 min later, aerosol administration; 10 min after aerosol administration, a standardized topical anesthesia was performed. As soon as the bronchofiberscope had entered the trachea, sounds were recorded for a 5-min period, while the tracheobronchial tree was systematically inspected. Additional lidocaine (2% solution, 2 ml boluses) was injected into the airways if troublesome cough occurred. The two groups did not differ significantly in terms of age, sex ratio, and smoking history. In contrast, both the number of coughs and the volume (ml) of additional lidocaine were significantly smaller in the fenoterol group than in the placebo group: m +/- SEM: 35.0 +/- 5.5 versus 51.6 +/- 6.5, p less than 0.01 and 1.9 +/- 0.5 versus 3.3 +/- 0.4, p less than 0.01, respectively. Thus, fenoterol exhibits antitussive properties and can usefully be administered before bronchofiberscopy.