From a theoretical point of view it may be hypothezised that cognitive deficits are not uncommon in patients with new-onset epilepsy since causative brain lesions, genetic influences and interictal epileptic activity are likely to exist even before the first unprovoked seizure. We reviewed the literature concerning cognitive deficits in genetically determined epilepsy-syndromes and studies on cognitive and psychiatric deficits in patients with new-onset epilepsy. In several animal models hints of memory deficits or learning disorders even before the manifestation of epileptic seizures were found. Some learning disorders showed characteristics of the human attention-deficit-hyperactivity-disorder. In familial frontal epilepsies specific associations between cognitive deficits as well as psychiatric syndromes and certain mutations were described. Cognitive deficits in adult patients with new-onset epilepsy were described several times with regard to delayed recall in verbal memory, selective attention and psychomotor performance. Depression and suicide attempts were increased before the first seizure. In childhood cognitive deficits were regarded as causative factors for behavioral problems, which sometimes were even found before the first recognized seizure. Verbal memory deficits at the onset of epilepsy seemed to be a risk factor for the development of a therapy refractory course. But on the basis of the published data it is impossible to state whether cognitive deficits after a first unprovoked seizure in adulthood indicate an increased risk of recurrent seizures apart from the results of MRI and EEG studies.