The metabolic syndrome (MetS) has previously been associated with an early marker of atherosclerosis, the carotid intima-media thickness (IMT). From the ISMIR (Ispessimento Medio Intimale e Rischio cardiovascolare [media-intima thickness and cardiovascular risk]) study population of 479 asymptomatic participants, we identified 80 participants with MetS. Carotid IMT and plaques were evaluated by ultrasonography. Blood samples were obtained from all participants. Participants with MetS had a significantly higher prevalence of a carotid IMT > 0.80 mm (P = .004) and of carotid plaques (P < .001) as compared with participants without MetS. Carotid IMT was significantly correlated with fasting triglycerides and fibrinogen levels both in participants with MetS and in those without MetS (all P < .01). In contrast, IMT correlated with fasting plasma glucose, serum creatinine, and uric acid levels only in participants without MetS. Our study confirms the association between MetS and carotid atherosclerosis. In MetS, a significant correlation between carotid IMT and triglycerides and fibrinogen levels was found.