Kohlschütter's syndrome is a combination of amelogenesis imperfecta, progressive mental retardation and epileptic seizures. We report on a patient with typical signs of this syndrome. Beneath severe enamal defects of teeth, the patient has been suffering from progressive mental and motoric retardation from the age of six months. Although there is pathologic activity in EEG, seizures have not yet appeared. MRT shows distinct signs of cerebral atrophy. Apart from this patient 15 patients in 4 families have been reported up to now in literature. The article compares diagnostic results in this case with those reported in literature.