The metabolic syndrome is a clustering of low levels of high-density lipoprotein cholesterol, hyperglycemia, high waist circumference, hypertension, and elevated triglycerides, and is associated with cardiovascular disease. Calcified atherosclerotic plaque in the coronary arteries (CAC), measured by cardiac tomographic scans, is a marker for atherosclerosis and relates to mortality. The investigators examined the relation of the metabolic syndrome, and each of its components, to the prevalence of CAC, measured from 2002 to 2004 in 3,166 white and African-American subjects in the National Heart, Lung, & Blood Institute Family Heart Study. Adjusting for age, race, center, smoking, and alcohol consumption, odds ratios and 95% confidence intervals (CI) for a CAC score >100 for subjects with metabolic syndrome were 1.7 (95% CI 1.3 to 2.3) for men and 1.6 (95% CI 1.2 to 2.1) for women. Associations were found for most of the components of the metabolic syndrome with CAC. Associations with the metabolic syndrome were similar for calcified atherosclerotic plaque in the abdominal aorta among 3,173 subjects, with adjusted odds ratios for a score >1,000 of 2.1 (95% CI 1.5 to 3.1) for men and 1.8 (95% CI 1.4 to 2.4) for women. We conclude that the metabolic syndrome and most of its components are associated with a higher prevalence of calcified atherosclerotic plaque in the coronary arteries and abdominal aorta in white and African-American men and women.