Homocysteine is a sulfurated amino acid used for the synthesis of methionine. The last decade's researches proved that hyperhomocysteinemia is an independent risk factor for atherosclerotic vascular disease. The vascular injury induced by several mechanisms of hyperhomocysteinemia is the hallmark of homocysteine's atherogenic properties. Hyperhomocysteinemia is present in 85% of the patients with chronic renal failure (cardiovascular diseases are the main cause of mortality) and persists after initiating dialysis or after renal transplantation. Although folic therapy or folinic acid therapy reduce homocysteine levels with 20-40% in hemodialysis patients, the effects on cardiovascular morbidity have yet to be proven in future studies.