Background: Elastic property of aorta is an important determinant of left ventricular function and coronary blood flow. However, limited evidence exists on whether non-invasively-measured aortic stiffness relates to the presence and degree of angiographically-confirmed coronary artery stenosis. We aimed to investigate the relationship between aortic distensibility (AoD) and coronary artery disease (CAD) in angina patients. Method: We enrolled a total of 212 patients with angina admitted to our institute for coronary angiography. Patients with acute myocardial infarction, significant aortic valvular disease, or aortic aneurysm were excluded. Transthoracic echocardiography using Acuson Sequoia C512TM system (Siemens, USA) with a 2.5 MHz transducer was performed to measure aortic diameters which were taken three times and averaged from M-mode tracing at ascending aorta 3 cm above the aortic valve. AoD was calculated from the aortic diameters and brachial artery pressure using the formula: 2 x (change in aortic diameters) /(diastolic aortic diameter) x (change in aortic pulse pressure). Patients were divided into three groups based on the angiographic findings: non-significant disease (luminal narrowing <50%, Mild CAD); single-vessel (1VD); and two- or three-vessel disease (MVD) with luminal narrowing >50%. Results: For baseline characteristics, there were no significant differences in age, sex, prevalence of hypertension, systolic or diastolic blood pressure, pulse pressure, aortic diameters, left ventricular mass index, highly sensitive C-reactive protein, triglyceride and low-density lipoprotein cholesterol between three groups. However, high-density lipoprotein (HDL) cholesterol was significantly higher in mild CAD group (49짹15 vs. 43짹9vs. 41짹10 mg/dL, p=0.01), and DM was more prevalent in MVD group (18% vs. 17% vs. 40%, p=0.01). AoD of mild CAD group was significantly higher than that of 1VD or MVD group (2.85짹2.47 vs. 1.82짹1.59 vs. 1.74짹1.44 10-3mmHg-1, p=0.01). On multiple logistic regression analysis, AoD and HDL-cholesterol were the independent variables predicting significant CAD (p=0.001 and p=0.005, respectively). AoD ��� 2.29 predicted the presence of significant CAD with the sensitivity of 72.3% (95% CI 62.2-81.1) and specificity of 54.5% (95% CI 36.4-71.9). Conclusion: AoD measured non-invasively at ascending aorta was independently associated with the degree of coronary atherosclerosis confirmed by angiogrphy in angina patients. Large elastic artery stiffening thus can be considered as a useful non-invasive marker of the severity of coronary atherosclerosis, providing the clinicians with information on the need to proceed to further invasive angiography in angina patients.