OBJECTIVE To explore the association between metabolic syndrome and atherosclerosis. METHODS Carotid intima-media thickness (IMT) was detected and the atherosclerotic plaque was classified, graded, and scored in 358 retired males, aged 55 approximately 74, including 95 (26.6%) with metabolic syndrome (metabolic syndrome group) and 263 (73.5%) without metabolic syndrome (non-metabolic syndrome group). The correlation of IMT with every characteristic of metabolic syndrome diagnostic criteria was studied. RESULTS The metabolic syndrome group had higher carotid IMT (0.90 mm +/- 0.12 mm versus 0.84 mm +/- 0.11 mm, P < 0.05), plaque score (3.58 mm +/- 0.44 mm vs 2.45 mm +/- 0.25 mm, P < 0.05), plaque occurrence rate (64.2% vs 47.5%, P < 0.05) and cardiovascular event morbidity (20.0% versus 12.2%, P < 0.05) compared with the non-metabolic syndrome group. IMT was significantly but weakly positively correlated with systolic blood pressure, diastolic blood pressure, glucose, and waistline (r = 0.27, r = 0.17, r = 0.17 and r = 0.12 respectively, all P < 0.05). CONCLUSIONS Metabolic syndrome accelerates the course of atherosclerosis. Detecting carotid artery as early as possible by vascular ultrasound is helpful to primary prevention of cardiovascular events in the patients with metabolic syndrome.