We studied the outcome of surgery in 500 patients over 80 years of age. Hospital mortality within one month of surgery was 6.2%. The American Society of Anesthesiologists class 1 to 5 preoperative evaluation scale was useful in predicting death--less than 1% of class 2 patients died, 4% of class 3, and 25% of class 4. Six of seven perioperative deaths were caused by mesenteric infarction. Myocardial infarction was the leading cause of postoperative death. Twenty-four percent of 141 patients who underwent upper abdominal surgery required controlled endotracheal ventilation for more than 24 hours postoperatively; 57% after intrathoracic surgery; and only 2% after surgery that did not enter pleura or peritoneum. Forty-seven patients underwent gallbladder surgery, and 27 peripheral underwent vascular surgery without any hospital fatality. Enflurane appears to be a safe general anesthetic for sick, elderly patients.