A high serum total homocysteine (tHcy) level is an independent risk factor for cardiovascular disease. In this study, we examined the relationship of tHcy levels with the components of the metabolic syndrome. Fifty one patients diagnosed as metabolic syndrome (median age: 38 (25-48) years) and 50 healthy subjects (median age: 35 (26-48) years) were included in the study. Total homocysteine levels were significantly higher in metabolic syndrome group than in the control group (24.2µmol/l vs. 13.4µmol/l). Vitamin B12 levels were significantly lower in metabolic syndrome group than in the control group (214pg/ml vs. 247pg/ml). In partial correlation, tHcy concentrations were unrelated to metabolic syndrome or to the components of the metabolic syndrome, including fasting serum triglycerides, HDL-cholesterol, fasting glucose, blood pressure, or body mass index. tHcy levels were only strongly related to the vitamin B12 concentrations. The risk of cardiovascular disease is higher in patients with metabolic syndrome compared to the normal population. High tHcy levels might be evaluated in this group of patients in addition to evaluation of the parameters of metabolic syndrome.