At the period 2000-2016 were observed 9 patients with Down syndrome (5 boys and 4 girls). Eight children with classic variant (47, XX,+ 21) and one boy with mosaicism (46, XX/47, XX,+ 21). Age of epilepsy onset varies from 1,5 month to 4 years; predominantly had manifestation in infancy (88,9%). The most part of patients with DS presented West syndrome (n=6, 66,7%), 2 patients with Markand-Blume-Ohtahara syndrome or severe epilepsy with multifocal independent spike foci -SE-MISF (22,2%) and one girl with focal frontal lobe epilepsy, Lennox-Gastaut-like phenotype (11,1%). Clinical remission was observed in 5 of 9 patients with DS (55,6%) and significant decreasing of seizures - in 4 (44,4%) of children. The most effective antiepileptic drugs were valproates in monotherapy and in combination with lamotrigine, benzodiazepines and barbiturates. Topiramate demonstrated good effectiveness at tonic seizures, but with aggravation of myoclonic. Carbamazepines demonstrated low effect with high aggravation risk, effectiveness of ethosuximide on seizures and discharges was confused by gastrointestinal problems and low appetite.