Epicardial adipose tissue (EAT) has been shown to have important effects on the development of coronary artery disease (CAD) through local paracrine influences on the vascular bed. We compared a cohort of asymptomatic patients with type II diabetes mellitus (DM) without known CAD to an age- and gender-matched group of asymptomatic patients without DM from the CTRAD (Cardiac CT's Role in Asymptomatic Patients with DM-II) study in which patients underwent a cardiac computed tomography angiogram, for early detection of CAD. Mean EAT volumes of 118.6 ± 43.0 and 70.0 ± 44.0 cm(3) were found in the DM and non-DM groups, respectively. When stratified by the presence and severity of CAD, it was found that in the DM (p = 0.003) and non-DM groups (p <0.001), there was a statistically significant increase in EAT volume as the patients were found to have increasingly severe CAD. After adjusting for age, race, gender, DM, hypertension, insulin use, body mass index, and coronary artery calcium (CAC) score, the presence of >120 cm(3) of EAT was found to be highly correlated with the presence of significant CAD (adjusted odds ratio 4.47, 95% confidence interval 1.35 to 14.82). We found that not only is EAT volume an independent predictor of CAD but that an increasing volume of EAT predicted increasing severity of CAD even after adjustment for CAC score.