To determine the risks of performing major surgical procedures on patients with chronic renal failure, the charts of twenty-nine hemodialysis patients who underwent thirty-eight elective and nine emergency operations were reviewed. Preoperative preparation included adequate hemodialysis of the patients, 88 per cent of whom were dialyzed within 24 hours of surgery. Azotemia was well controlled prior to administration of anesthesia. The average preoperative hematocrit was 26 per cent, and only one patient was hyperkalemic preoperatively. There were no intraoperative complications attributable to the patients' impaired renal function. Postoperative complications were frequent and are discussed in detail. Hemodialysis was done immediately postoperatively in five patients and on the first postoperative day in twenty-three additional patients with no problems. There were only two deaths (4.3 per cent) in the series. With careful monitoring during the perioperative period, major surgical procedures can safely be performed on patients with chronic renal failure.