Over the last two decades, various studies have shown that moderate and persistent hyperhomocysteinemia is implicated in the development of atherosclerosis, which is responsible for 50% of all mortality and morbidity in Western countries. Considering that the most traditional risk factors for heart disease and stroke, such as plasma lipids, cigarette smoking, hypertension, obesity, and diabetes, only account for 50% of cardiovascular disease (1,2), one can understand the reason why homocysteine (Hcy) measurement is included in he list of tests for investigating the causes of atherosclerosis and thrombosis.