Although there are numerous reports of interictal psychosis in epileptic patients, there are few studies describing the longitudinal course and treatment of postictal psychosis. The goal of this study was to define the clinical features, natural history, and possible interventional methods in a group of patients with complex partial seizures and postictal psychosis. We studied seven patients who manifested psychotic behavior following an increase in their seizure frequency. Mean follow-up was 83 months. Patients underwent neuropsychiatric testing, cranial magnetic resonance imaging, and extensive EEG evaluation. All but one patient had severe epilepsy. An increased number of seizures was followed by a brief period of lucidity and then psychosis, which lasted between 2 and 14 days and tended to recur (mean, one episode every 4 months). EEGs done during the psychotic episodes generally demonstrated a mild diffuse background slowing without evidence of ictal epileptiform discharges. Evaluation between episodes revealed no persistent psychiatric features. The patients rarely required hospitalization or neuroleptic medications. Patients usually responded to mild sedation, close observation, and a supportive environment.