Background: Resistin is an adipocyte-secreted hormone. Resistin impairs glucose homeostasis and insulin action in the mouse. However, in human, the association between resistin and insulin resistance or obesity is controversial. It was recently reported that plasma resistin concentrations are elevated in patients with type 2 diabetes. Relationship between circulating resistin concentrations and atherosclerotic coronary artery disease(CAD) in type 2 diabetic patients is not yet known. Objectives: We investigated serum resistin concentrations in type 2 diabetic patients with atherosclerotic CAD compared with those without CAD. Methods: Diabetic patients who had organic stenosis of at least 1 major coronary artery, were classified as CAD patients (DMCAD). Controls were characterized by no history of angina or other heart disease, a normal resting ECG and a normal ECG during exercise testing. We measured fasting serum resistin, adiponectin, leptin concentrations in 31 DMCAD and 47 DM control patients. Results: Serum resistin levels were higher in type 2 diabetic patients with CAD than in those without CAD (5.75짹0.58 vs. 2.53짹0.37 ng/mL (mean짹SEM), p<0.001), and this difference still persisted, irrespective of sex or BMI. Insulin resistance index assessed by homeostasis model assessment (HOMA-IR) was significantly correlated with resistin (r=0.4, p<0.001), but HOMA-IR was not an independent factor associated with resistin by multivariate analysis. Serum resistin concentrations did not show a significant correlation with weight, BMI, blood pressure, plasma lipoprotein concentrations, fasting glucose, insulin, adiponectin, or leptin levels. In type 2 diabetic patients with CAD, serum resistin levels were not different between one vessel diseased group and multivessel diseased group. Serum leptin levels were higher in type 2 diabetic patients with CAD than in those without CAD, but this difference was not significant when adjusted for BMI. Serum adiponectin levels were not different between the two groups. Conclusions: Serum resistin concentrations are elevated in type 2 diabetic patients with CAD, compared with those without CAD.