Background: Desflurane has very short induction time because its physical characteristics. But its pungent odor and tendency to irritate the upper airway make it unsuitable for induction of anesthesia. This study was performed to determine what time is prefer to start the desflurane inhalation. Methods: Forty adults (17-45 years) were enrolled in a randomized, double-blind study. Twenty start desflurane inhalation just after loss of consciousness, and the others received desflurane after intubation. We monitored vital signs, BIS, desflurane concentration, rocuronium injection pain response, and airway irritation signs. Results: The demographic data were not different two groups. Early inhalation group showed more stable cardiovascular response than that of late inhalation group. But rocuronium injection pain response and airway irritation sings were not different between two groups. Conclusions: Early inhalation of desflurane (6 vol%) just after loss of consciousness attenuates cardiovascular responses during intubation.