Background: The carotid intima-media thickness(CIMT), a precursor to preclinical atherosclerosis has been consistently linked to cardiovascular disease(CVD) and also the metabolic syndrome(MS) is a clustering of cardiovascular risk factors. The evidence for the clinical implications of the CIMT in age-related groups with MS is not well established. Methods: Among the 3714 patients who have undergone carotid ultrasound at our institution, 1465 patients (M:F=855:610, mean age=58짹12) who had normal coronary artery confirmed by coronary angiography and no diabetes were enrolled in this study. The carotid intima, media, and IMT were compared with different age groups divided by the young adult group(under 44 years old, 203 subjects M:F=47:156, mean age=37짹7) and the older adult group(over 65 years old, 458 subjects, M:F=208:250, mean age=71짹5). We excluded middle-aged adults(45-64 years old). In the young adult group, 65(32%) patients were diagnosed as the metabolic syndrome by National Cholesterol Education Program(NCEP) criteria. In the older adult group, 175(38%) patients were diagnosed as the same way. Results: There were significant difference in right maximal, mean, left maximal, mean, intima, medial thickness between young adults with and without MS. But in older adult, the both CIMT were no difference with/without metabolic syndrome(see the table). Conclusion: The assessment of CIMT is a useful screening method for detecting early atherosclerosis in young adults with MS.