Epicardial adipose tissue (EAT) is emerging as a risk factor for coronary artery disease (CAD).The aim of this study was to determine the applicability and efficiency of automated EAT quantification.EAT volume was assessed both manually and automatically in 157 patients undergoing coronary CT angiography. Manual assessment consisted of a short-axis-based manual measurement, whereas automated assessment on both contrast and non-contrast-enhanced data sets was achieved through novel prototype software. Duration of both quantification methods was recorded, and EAT volumes were compared with paired samples t test. Correlation of volumes was determined with intraclass correlation coefficient; agreement was tested with Bland-Altman analysis. The association between EAT and CAD was estimated with logistic regression.Automated quantification was significantly less time consuming than automated quantification (17 ? 2 seconds vs 280 ? 78 seconds; P <.0001). Although manual EAT volume differed significantly from automated EAT volume (75 ? 33 cm(?) vs 95 ? 45 cm(?); P <.001), a good correlation between both assessments was found (r = 0.76; P <.001). For all methods, EAT volume was positively associated with the presence of CAD. Stronger predictive value for the severity of CAD was achieved through automated quantification on both contrast-enhanced and non-contrast-enhanced data sets.Automated EAT quantification is a quick method to estimate EAT and may serve as a predictor for CAD presence and severity. Society of Cardiovascular Computed Tomography.