A retrospective study was made of the postoperative course of 90 patients submitted to "en bloc" temporal lobectomy for intractable epilepsy. Particular attention was paid to the pattern of recurrent seizures after operation. Follow-up periods of at least 5 years were available for 60 patients and a further 47 patients were followed up for periods of between 5 and 12 years after surgery. Three postoperative courses were observed, failure of the treatment in which the seizure frequency was changed by less than 75% (21% of the total), a partial relief of seizures in an intermediate group (21%) and a successful result in the remainder (58%) although only 25% of the total remained constantly fit-free. The recurrence of fits after a long fit-free interval is described and discussed.