It has been well known that some volatile anesthetic agents produce oxidative stress. Desflurane as a new volatile agent might have limited oxidative toxic effect because it is relatively a new short-acting anesthetic characterized by a short duration of action and a quick postanesthetic recovery. We investigated effect of desflurane on serum glutathione peroxidase (GSH-Px), lipid peroxidation (LP), vitamin E, and erythrocyte superoxide dismutase (SOD) values in patients. Fifteen adult patients are scheduled for elective surgery, ASA I or II physical status. Tidal volume and ventilation frequency were kept unchanged during the operation. Baseline values in venous blood samples were preoperatively taken and blood was also taken postoperatively at the 1st and the 12th hours of desflurane exposure. LP levels were significantly (p<0.05) higher postoperatively at 1st hour than in preoperative values while a-tocopherol concentration WS significantly (p<0.001) lower in postoperative period at 1st hour than in preoperative period. Erythrocyte SOD and serum GSH-Px activities did not differ between pre- and postoperative periods. In conclusion, we observed that desflurane produced oxidative stress by decreasing a-tocopherol levels. Use of vitamin E may be possible to reduce the oxidative effect of desflurane. Copyright (C) 2010 John Wiley & Sons, Ltd.