We sought to evaluate the association between plasma levels of monocyte chemoattractant protein(MCP)-1 and the risk for subclinical atherosclerosis. Monocyte chemoattractant protein is a chemokine that recruits monocytes into the developing atheroma and may contribute to atherosclerotic disease development and progression. Plasma levels of MCP-1 are independently associated with prognosis in patients with acute coronary syndromes, but few population-based data are available from subjects in earlier stages of atherosclerosis. In the Dallas Heart Study, a population-based probability sample of adults in Dallas County ≤65 years old, plasma levels of MCP-1 were measured in 3,499 subjects and correlated with traditional cardiovascular risk factors, high-sensitivity C-reactive protein(hs-CRP), and coronary artery calcium(CAC) measured by electron beam computed tomography. Higher MCP-1 levels were associated with older age, white race, family history of premature coronary disease, smoking, hypertension, diabetes, hypercholesterolemia,and higher levels of hs-CRP (p< 0.01 for each). Similar associations were observed between MCP-1 and risk factors in the subgroup of participants without detectable CAC. Compared with the subjects in the lowest quartile of MCP-1, the odds of prevalent CAC (CAC score ≥10) for subjects in the second, third, and fourth quartiles were 1.30 (95%confidence interval 0.99 to 1.73), 1.60 (95%CI 1.22 to 2.11), and 2.02 (95%CI 1.54 to 2.63), respectively. The association between MCP-1 and CAC remained significant when adjusted for traditional cardiovascular risk factors, but not when further adjusted for age. In a large population-based sample, plasma levels of MCP-1 were associated with traditional risk factors for atherosclerosis, supporting the hypothesis that MCP-1 may mediate some of the atherogenic effects of these risk factors. These findings support the potential role of MCP-1 as a biomarker target for drug development. We sought to evaluate the association between plasma levels of monocyte chemoattractant protein (MCP) -1 and the risk for subclinical atherosclerosis. Monocyte chemoattractant protein is a chemokine that recruits monocytes into the developing atheroma and may contribute to atherosclerotic disease development and progression. of the MCP-1 are independently associated with prognosis in patients with acute coronary syndromes, but few population-based data are available from subjects in earlier stages of atherosclerosis. In the Dallas Heart Study, a population-based probability sample of adults in Dallas County ≤ 65 years old, plasma levels of MCP-1 were measured in 3,499 subjects and correlated with traditional cardiovascular risk factors, high-sensitivity C-reactive protein (hs-CRP), and coronary artery calcium (CAC) measured by electron beam computed tomography. Higher MCP-1 levels were associated with older age, white race, family history of premature coronary disease, smoking, Compared with the subjects in the lowest quartile of p-0.01 and each of the subjects in the subgroup of participants without detectable CAC. Compared with the subjects in the lowest quartile of MCP-1, the odds of prevalent CAC for CAC score ≥10 for subjects in the second, third, and fourth quartiles were 1.30 (95% confidence interval 0.99 to 1.73), 1.60 (95% CI 1.22 to 2.11), and 2.02 (95% CI 1.54 to 2.63), respectively. The association between MCP-1 and CAC remained significant when adjusted for traditional cardiovascular risk factors, but not when further adjusted for age. In a large population-based sample, plasma levels of MCP- 1 were associated with traditional risk factors for atherosclerosis, supporting the hypothesis that MCP-1 may mediate some of the atherogenic effects of these risk factors. These findings support the potential role of MCP-1 as a biomarker target for drug development.