We have compared sedation for fibreoptic bronchoscopy provided by incremental doses of midazolam with that provided by a computer-controlled infusion of propofol. These two methods were compared in terms of operator and patient acceptability, anxiolysis, effects on systolic arterial pressure and oxygen saturation. Tests were made also of memory and motor reactions, before and 60 min after the end of the procedure. Acceptability to operators and patients was high in both groups. There were no significant differences between the groups in systemic arterial pressure or anxiolysis. Oxygen saturation decreased in both groups (propofol group median 83% (range 69-95%); midazolam group median 86% (range 77-95%)) (ns). The median recovery time was 5 min (range 5-10 min) in the propofol group and 10 min (range 5-40 min) in the midazolam group (P < 0.01). Memory and motor reaction times 60 min after the end of the procedure did not differ from baseline in the propofol group, but were significantly impaired in the midazolam group.