Of 61 newborns with disorders in amino acid metabolism, 20 had seizures; 15 of them have been recorded. Clinically, seizures are mostly partial clonic jerks. There seems to be some homogeneity of EEG features in relation to causal amino acidopathy. In every case where seizures, either electroclinical or only infraclinical, occurred the evolution was very poor, even in those diseases that would have had a good prognosis. Therefore the EEG in the newborns is especially interesting, both as an aid to diagnosis by interictal recording and as a prognostic tool by registration of seizures.