Epicardial adipose tissue (EAT), which is thought to be a component of visceral adiposity, is associated with the metabolic syndrome. We aimed to test the hypothesis that echocardiographic EAT thickness can be a marker for the presence and severity of coronary artery disease (CAD).In all, 150 patients (100 patients with CAD and 50 patients with normal coronary arteries by diagnostic coronary angiography; 65 women, 85 men; mean age 55.7±7.4years) were enrolled. EAT thickness was measured using 2-D echocardiographic parasternal long- and short-axis views. EAT thickness measurements were compared with angiographic findings.EAT thickness was significantly higher in patients with CAD in comparison to those with normal coronary arteries (6.9±1.5mm vs. 4.4±0.8mm; P<0.001). Furthermore, EAT thickness increased with the severity of CAD (multivessel disease 7.4±1.2mm vs. single vessel disease 5.7±1.7mm; P<0.001). Gensini's score significantly correlated with EAT thickness (r=0.600, P<0.001). EAT thickness of ≥5.2mm had 85% sensitivity and 81% specificity (ROC area 0.914, P<0.001, 95% CI [0.86–0.96]) for predicting CAD.EAT thickness, which is easily and non-invasively evaluated by transthoracic echocardiography, can be an adjunctive marker to classical risk factors for the prediction of CAD.