Whereas cardiovascular risk factor levels are substantially different in black and white Americans, the relative rates of cardiovascular disease in the 2 groups are not always consistent with these differences. To compare the prevalence of coronary calcification, an indicator of coronary atherosclerosis, in young adult blacks and whites, we performed electron-beam computed tomography of the heart in 443 men and women aged 28 to 40 years recruited from a population-based cohort. The presence of calcium, defined as at least 1 focus of at least 2.05 mm(2) in area and >130 Hounsfield units in density within the coronary arteries, was identified in 16.1% of black men, 11.8% of black women, 17.1% of white men, and 4.6% of white women (P=0.04 for comparison across groups). Coronary calcium was associated with age and male sex, and after adjustment for age, race, and sex, coronary calcium was positively associated with body mass index, weight, systolic blood pressure, total cholesterol, low density lipoprotein cholesterol, triglycerides, and fasting insulin and negatively associated with education (all P<0.05). Independent risk factors included male sex, body mass index, and low density lipoprotein cholesterol. Race was not significantly associated with coronary calcium in men or women, before or after adjustment for risk factors. Coronary calcification is associated with increased levels of cardiovascular risk factors in young adults, and its prevalence is not significantly different in blacks and whites.