Homocysteine (HMC) is a sulfur containing amino acid, which plays a role in methionine metabolism. Folic acid (FA) and vitamin B12 (B12) are essential for remethylization of HMC to methionine. HMC level increases in the deficiency of these vitamins. Hyperhomocysteinemia causes vascular endothelial damage, which causes atherosclerosis. The aim of this study is to investigate the effect of valproate (VA) and carbamazepine (CBZ) on the serum levels of HMC, B12, and FA.