The metabolic syndrome is associated with increased risk of cardiovascular disease. It is important to examine the relation of the metabolic syndrome with the early stages of atherosclerosis. We sought to determine the impact of the metabolic syndrome, defined with International Diabetes Federation criteria, on arterial pulse wave velocity.Four hundred fifty-eight Korean adults (aged 26-77 years) were recruited into this cross-sectional study. Subjects were not taking any drugs other than antihypertensive or antidiabetic medication. All subjects were examined for body mass index, blood pressure, lipid profile, hs-CRP, uric acid, cystatin C, fasting glucose, and brachial-ankle pulse wave velocity. The prevalence of the metabolic syndrome by International Diabetes Federation definition was 20.7%. A positive correlation was observed between blood pressure, total cholesterol, triglycerides, uric acid, cystatin C, waist circumference, fasting glucose, and the brachial-ankle pulse wave velocity (P < 0.05). Subjects with metabolic syndrome had significantly higher arterial pulse wave velocity than subjects without metabolic syndrome. Multivariate logistic regression analysis adjusted for sex, age, and current smoking status showed that metabolic syndrome was associated with increased risk of high arterial pulse wave velocity (odds ratio: 3.31) (P < 0.05).Metabolic syndrome is associated with arterial stiffness by arterial pulse wave velocity. Monitoring of arterial pulse wave velocity in patients with metabolic syndrome may be helpful in identifying persons at high risk for subclinical atherosclerosis.