Propofol, a new intravenous sedative agent, was investigated in 41 asthmatic patients undergoing day-case (outpatient) fiberoptic bronchoscopy. The study design was a randomized comparison between propofol and midazolam, which is a well-established intravenous sedative agent. The age, weight, and American Society of Anesthesiologists physical status and lung function of the two groups were not significantly different. Mean (SD) induction dose of propofol was 104.7 (30.1) mg with a maintenance dose of 121.9 (38.5) mg. Corresponding values of midazolam were 9.3 (3.1) mg and 3.7 (2.3) mg. The required level of sedation was achieved significantly faster with propofol, mean (SD) 125.4 (39.8) s, compared with midazolam, 179.4 (55.2) s (p < 0.001). Significantly faster recovery was noted with propofol compared with midazolam in terms of time to recall name and date of birth 2.3 (1.7) min vs 6.3 (8.6) min, (p < 0.045). Alertness scored with the digital symbol substitution test (DSST) returned to prebronchoscopy values in the propofol group at 30 min, DSST score = 35.9 (18.2) vs 13.4 (9.1), in the midazolam group (p < .0001) and was still significantly higher at 90 min-39.4 (17.9) and 23.1 (13.8) (p < 0.01). We conclude that propofol is a useful sedating agent in fiberoptic bronchoscopy with similar efficacy to midazolam but with a faster onset of action and a more rapid recovery. These represent significant advantages for day-case procedures.