Background Insulin resistance is one of the underlying causes for atherosclerosis. The monocyte chemoattractant protein-1 (MCP-1) plays a crucial role in initiating atherogenesis by recruiting monocytes/macrophages to vessel wall. In this study, we investigated the relationship between homeostasis model assessment-estimated insulin resistance (HOMA-IR) and circulating level of MCP-1 in healthy adults. Methods: By reviewing the medical records of 171 healthy adults, we determined the circulating level of MCP-1, body mass index, systolic blood pressure, diastolic blood pressure, triglycerides, total cholesterol, LDL- cholesterol, HDL-cholesterol, fasting glucose, fasting insulin level and HOMA-IR. We studied the relationship between the variables by Pearson correlation coefficients and multiple linear regression analysis. Results: MCP-1 correlated positively with HOMA-IR (r=0.28; P<0.01). Age, systolic blood pressure, diastolic blood pressure, triglycerides, LDL-cholesterol, fasting glucose and insulin level also showed stastically significant correlation. Age, gender, HOMA-IR were the variables which affected MCP-1 by multiple regression analysis adjusting for body mass index, systolic blood pressure, triglycerides, and LDL-cholesterol. Conclusion: In our study, circulating levels of MCP-1 were associated with insulin resistance. These findings support the potential role of MCP-1 as a biomarker for subclinical atherosclerosis. (J Korean Acad Fam Med 2008;29:189-194)