A relationship between serious psychiatric disorders and epilepsy has been observed since antiquity. An association between schizophrenia and epilepsy has been noted since the turn of century, but this relationship appeared to be uncertain. From the 1950s on, a number of studies were devoted to this subject. Epileptic patients are more risk for psychosis than the general population. Others psychiatric syndromes, some of which have been individualized recently, can occur in patients with epilepsy: alternative psychosis, affective states, postictal psychoses, postoperative psychoses. In this article we present the different aspects of the psychoses of epilepsy. Their knowledge allows in most cases a precise diagnosis and an appropriate treatment.