We experienced anesthetic management of two patients with insulinoma in whom frequent hypoglycemic episodes with blood glucose levels of 39-42 mg.dl-1 had been observed. Each patient received epidural analgesia with a catheter inserted at the T 9/10 intervertebral space. Anesthesia was induced with propofol 80-100 mg and fentanyl 200 micrograms. Tracheal intubation was facilitated with vecuronium 6 mg. Anesthesia was maintained with continuous infusion of propofol and epidural anesthesia. Rapid measurements of immunoreactive insulin (IRI) were useful for localization of insulinoma during surgery. Perioperative plasma glucose levels could be maintained within normal ranges by continuous infusion of glucose. Rebound hyperglycemic episodes were not observed, and IRI was reduced after removal of the insulinoma. General anesthesia using propofol and epidural block is a useful choice for the anesthetic management of patients undergoing an operation for removal of an insulinoma.