Major surgery in 400 elderly men presented a special, multidisciplinary problem because of coexisting diseases, decreased physiologic resiliency, psychologic inertia, and unpredictable rehabilitation potential. Well-preserved septuagenarians survived pneumonectomy, octogenarians survived gastric resection, and nonagenarians endured cholecystectomy with complete recovery. Complications were chiefly pulmonary and nutritional, were associated with exhaustion and infection, and were followed by either recovery or hypoxic death from terminal pulmonary insufficiency. Errors in judgment and technique in the preoperative, and/or postoperative periods accounted for most complications. The aged required intensive postoperative nursing care. Their convalescence was slightly prolonged, but surgery did not make existence intolerable. The age limit to human tolerance of any surgical procedure is unknown.