We sought to examine the relative contribution to cardiovascular risk of the metabolic syndrome (MS) compared with that of a high LDL cholesterol level in a population-based study of 2493 men and women, age 41-72 years, without major cardiovascular diseases at baseline. MS was defined according to the National Cholesterol Education Program criteria. The study population was subdivided into four groups on the basis of presence (prevalence: 15%) or absence of MS (85%) and presence (15%) or absence of high LDL cholesterol (85%) defined as a level >5.02 mmol/L or </=5.02 mmol/L. After 9.5 years, 233 had a cardiovascular endpoint (cardiovascular death, ischemic heart disease, and stroke). In proportional-hazard models, adjusting for age, sex, and smoking, and with subjects without MS and LDL cholesterol </=5.02 mmol/L as reference (73%), the relative risk of an endpoint (95% CI) was 1.49 (1.04-2.13) in participants without MS and LDL cholesterol >5.02 mmol/L (12%), 1.80 (1.26-2.57) in subjects with MS and LDL cholesterol </=5.02 mmol/L (12%) and 3.21 (1.99-5.17) in participants with both MS and LDL cholesterol >5.02 mmol/L (3%). In a general population, MS was associated with a cardiovascular risk comparable with that of a high LDL cholesterol level.