Methods and Materials: 30 patients underwent ATP stress dynamic CTP without table movement using a 256-slice MDCT and both CCTA and invasive coronary angiography (ICA). Dynamic CTP (whole heart datasets with 20 sample times in 40 beats in systole) was acquired with prospective ECG- gating. Obstructive CAD was defined as more than 50% stenosis on CTA or ICA, respectively. Quantitative CTP assessment of myocardium was performed according to the AHA 16 segment model. Myocardial peak CT attenuation value (HU), peak enhancement value (ΔHU), enhancement ratio (peak myocardial enhancement ΔHU / peak aortic enhancement ΔHU) and time to peak (ttp) enhancement were evaluated. Results: On CCTA 40 segments were classified as normal, 29 had coronary stenosis and 7 were excluded. CAG: 20 normal and 21 stenotic vessels. CCTA defined normal and ischemic myocardium showed mean peak CT attenuation values of 154±24 HU vs. 142±27 HU (p < 0.05), enhancement values of 100±23ΔHU vs. 87±25ΔHU (p < 0.05), enhancement ratios of 0.21±0.03 vs. 0.18±0.04 (p < 0.01) and ttp enhancement of 8.9±2.5s vs. 8.05±1.0s (p=0.49). ICA defined normal and ischemic myocardium showed mean peak CT attenuation values of 149±27HU vs. 142±34HU (p<0.05), enhancement values of 95±25ΔHU vs. 87±32ΔHU (p=0.39), enhancement ratios of 0.19±0.03 vs. 0.17±0.05 (p < 0.05) and ttp enhancement 8.3±1.5s vs. 8.2±1.0s (p=0.67). Conclusion: Ischaemic myocardium in the territory of stenotic coronary arteries can be identified using cut-off points for peak CT attenuation, enhancement and ehancement ratio.