Of 298 patients who had temporal lobectomies for intractable epilepsy, 4 (1.3%) developed post-ictal psychosis for the first time after surgery. All were males of normal intelligence with no pre-operative psychiatric disorder. Psychosis followed both complex partial and generalised seizures. The psychotic symptoms showed polymorphic features. Right temporal lobectomy may increase the susceptibility to post-ictal psychosis in patients who are not seizure free after surgery, particularly in the first postoperative year.