Background Computed tomography (CT) enables detection of coronary artery stenoses, but its use is limited by deficient evaluation at elevated heart rates. The accuracy of dual-source CT (DSCT) for the detection of coronary artery disease (CAD) was assessed in 76 patients at high probability of CAD without heart rate control and compared with quantitative coronary angiography (QCA). Methods and Results The 76 patients (47 males, mean age 65.5±10 years) underwent DSCT without preceding heart rate control. Data sets were evaluated by 2 observers in consensus with respect to stenoses >50% decreased diameter. QCA served as the standard of reference. Mean heart rate during scanning was 68±9 beats per min, and the average Agatston score was 337±560. Of 1,160 coronary artery segments, all but 3 were visualized artefact-free; 58 coronary stenoses were correctly detected by CT angiography. In the segment-based analysis, sensitivity was 98.3%, specificity 99.2% and accuracy 99%; patient based analysis revealed a sensitivity of 100%, specificity of 83.3% and overall accuracy of 92.1%. Conclusions Even at elevated heart rates, DSCT can reliably detect coronary artery stenoses and the results correlate well with those for invasive coronary angiography. (Circ J 2009; 73: 316 - 322)