Red blood cell (RBC) alpha-tocopherol and fatty acid levels in children undergoing long-term antiepileptic therapy were examined. Antiepileptic drugs included diphenylhydantoin (PHT), valproic acid (VPA), phenobarbital (PB), and carbamazepine (CBZ). RBC alpha-tocopherol levels were low in patients receiving multi-drug combination therapy, as compared with children receiving no treatment (controls), but plasma alpha-tocopherol levels were the same in both groups. With respect to fatty acid composition in RBCs, docosahexaenoic acid (DHA) level was decreased in children receiving antiepileptic therapy, while no changes were documented in the other fatty acids.