Purpose: Atherosclerosis is known to be a cause of various cardiovascular disease and causes fatal coronary artery disease (CAD). The carotid initma-media thickness (IMT) is noninvasive measures of atherosclerosis. In our study, we evaluated the association between IMT, and extent, severity of CAD on multidetector computed tomography (MDCT). Methods: 189 patients with known or suspected CAD were included in this study. The patients had no prior history of revascularization. In carotid ultrasonography, common carotid artery mean IMT was assessed and plaque score (PS) by summing all plaque thicknesses was calculated. The patients were classified into no CAD, non-obstructive CAD (luminal stenosis ���50% and obstructive CAD ( luminal stenosis >50%). And the number of segments with coronary plaque on MDCT was evaluated. Results: Significantly higher values of IMT and PS were observed in patients with CAD compared with no CAD (IMT-0.79짹0.18mm vs. 0.66짹0.17mm, PS-2.62짹5.81 vs. 1.01짹3.20, respectively, p<0.001). The mean IMT and PS in patients with obstructive CAD were significantly higher than non-obstructive CAD (IMT-0.82짹0.19mm vs. 0.76짹0.16mm, PS-3.03짹5.42 vs. 2.15짹3.25, respectively, p<0.001). Extent of coronary plaques presenting as the number of segments with plaques was positively correlated with IMT and PS (p<0.001 and p<0.001). On multivariate regression analysis after adjustment significant traditional cardiovascular risk factors, mean IMT was independent predictor for the presence of CAD and obstructive CAD (OR 32.56, p=0.005 and OR 12.40, p=0.011). Conclusions: Our data suggest that mean IMT is associated with presence and extent of CAD, and IMT might be useful to predict CAD.