The aim of this study was to evaluate the influence of antiepileptic therapy on antioxidant enzyme activity and lipid peroxidation in the erythrocytes of children with epilepsy. For this purpose, the activity of superoxide dismutase, glutathione peroxidase, and glutathione reductase and the malondialdehyde concentration in 61 healthy children and 90 children with epilepsy were measured. The activities of all of these enzymes were insignificantly higher, whereas the malondialdehyde concentration was significantly lower in the patients treated with carbamazepine monotherapy. In patients treated with valproate monotherapy, the activities of all enzymes were insignificantly lower, whereas the malondialdehyde concentration was insignificantly higher. In patients treated with polytherapy, the activity of superoxide dismutase was insignificantly lower, whereas the activity of glutathione peroxidase and glutathione reductase was insignificantly higher and the malondialdehyde concentration was lower. There were differences in glutathione reductase activity between the valproate monotherapy group and both the carbamazepine monotherapy and polytherapy groups and in malondialdehyde concentrations between the carbamazepine and valproate groups. The results indicate that the oxidant-antioxidant balance in children with epilepsy is modified by antiepileptic therapy.