Objective To analyze the diagnostic efficacy of computer aided analysis of relevant coronary artery stenosis using dual source computed tomography (DSCT). Methods In a larger scale study patients scheduled for conventional coronary angiography (CA) were additionally examined with DSCT. Based on a 13-segment model 30 CT scans of this study population were analyzed for significant stenosis using conventional 3D charts (3D) as well as a specialized cardiac analysis tool (CAT). Diagnostic accuracy and time to diagnosis was recorded for each vessel separately as well as the three readers’ confidence. Results With severe coronary artery calcifications, 53 false interpretations of segments were found for the total of 390 coronary segments analyzed. 3D and CAT analysis showed a Sensitivity, Specificity, PPV and NPV of 0.59, 0.91, 0.57, 0.92 and 0.57, 0.92, 0.56, 0.92, respectively. No significant differences in diagnostic accuracy could be found between 3D and CAT (P = 0.1667). 3D took a mean of 5.2 min (3–10 min). With CAT a mean time of 8.2 min (4–12 min) was needed. No significant inter-reader time differences (P = 0.4954) and no significant confidence level differences were found between readers and analyzes. Conclusion CAT of the coronary tree shows comparable accuracy to manual 3D analysis but needs improvements concerning coronary tree segmentation times.