High low-density lipoprotein (LDL) cholesterol and the presence of metabolic syndrome (MS) are established risk factors for clinical and subclinical cardiovascular disease (CVD). However, the relative contribution to CVD risk of MS and high LDL cholesterol is not well defined. Therefore, the aim was assess the relative risk for the presence of coronary artery calcification (CAC) with metabolic syndrome (MS) compared with that of moderate or high LDL cholesterol. A total of 440 consecutive asymptomatic men (mean age 46 +/- 7 years, range 29 to 65) presenting for CVD risk stratification were studied. MS was defined using National Cholesterol Education Program Adult Treatment Panel III criteria (n = 112; 24%). Moderate LDL cholesterol was defined as 130 to 159 mg/dl, and high LDL cholesterol as >/=160 mg/dl (n = 76; 17%). Overall, CAC was observed in 190 men (40%). The prevalence of CAC >0 was lowest in MS-negative men with LDL cholesterol <130 (35%) or 130 to 159 mg/dl (34%) and highest in MS-positive men with LDL cholesterol >/=160 mg/dl (80%). MS-positive men with LDL cholesterol of 130 to 159 mg/dl had CAC prevalence similar to that of MS-negative men with LDL cholesterol >/=160 mg/dl (54% vs 57%, respectively). This relation persisted with additional adjustment for age, smoking status, and cholesterol-lowering medication. In logistic regression analyses, the odds ratio for CAC >0 was highest in MS-positive men combined with high LDL cholesterol. In conclusion, these results suggest that the risk of CAC in asymptomatic men with moderate or high LDL cholesterol is magnified in persons with MS.