In epilepsy patients, psychotic states are related to a group of psychotic disorders with a specific phenomenology in which potential pathophysiological mechanisms are believed to be closely related to the epileptic disorder itself. Postictal psychosis is a very specific syndrome in relation to seizure activity: a clear temporal relationship exists between the psychotic state of sudden onset and a precipitating bout of complex partial or generalized seizures, with a characteristic lucid interval which lasts from two to 120h. The psychotic state may be related to the withdrawal of anticonvulsants, often in connection with video-EEG monitoring. The phenomenology of the psychotic state is often pleomorphic, with abnormal mood, paranoid delusions and hallucinations, with some clouding of consciousness or no evidence of impaired consciousness. The outcome is characterized by a remission of the psychotic symptoms over several days (mean: 1 week), with or without neuroleptic treatment. The majority of the patients suffer from complex partial seizures with frequent psychic auras that secondarily become generalized. In the majority of cases, prepsychotic EEG abnormalities persist during the psychosis. Frequent bitemporal foci are recorded on the EEG and MRI abnormalities (including mesial temporal sclerosis) are seen in more than half of the cases. The results of clinical, morphologic and metabolic available studies will be briefly discussed.