The results of the surgical treatment of epilepsy were studied in 44 patients 10 or more years after operation. Thirty-seven patients underwent operation only once; these patients were observed 11-26 years postoperatively. Seven patients had a recurrence within 5 years after operation and required a second operation; these patients were observed 11-17 years after the second operation. Recovery persisted for 15-27 years in 32 patients. There was a recurrence in 12 cases 11-19 years after operation. With one exception, these recurrences were satisfactorily treated medically.