We investigated the association between atherosclerosis of the thoracic aorta and the severity and extent of coronary atherosclerosis detected by multidetector computed tomography (MDCT) coronary angiography. In 122 patients, atherosclerotic plaque was scored from 0 to 4 points by the percentage of the luminal surface at the cross-sectional area of proximal, mid, and distal segments of the descending aorta. Critical coronary atherosclerosis was defined as lesions causing >50% luminal narrowing. Atherosclerotic plaque score of the descending aorta was associated with the severity (noncritical: 2.95 +/- 1.45 vs critical: 4.09 +/- 2.25, P < .001) and extent of coronary atherosclerosis (Kruskal-Wallis test, P < .005). Logistic regression revealed that aortic plaque score was as an independent risk factor associated with the severity of coronary artery disease (OR 1.32, 95% CI 1.01-1.73, P < .05). Atherosclerotic plaque burden of the descending aorta was associated with the extent and severity of coronary atherosclerosis.