We aimed to assess the correlation between angiographic and physiologic evaluation of coronary lesions in aortic stenosis (AS) patients presenting with intermediate coronary stenoses at the angiography. From 2002 to 2010, we included 163 patients from 2 centers with both AS and coronary artery disease (CAD), matched by age and gender with 163 contemporary patients with CAD alone. With both quantitative coronary angiography and fractional flow reserve (FFR), we assessed 259 coronary stenoses in the AS + CAD group, and 256 in the CAD alone group. A significant correlation was found between diameter stenosis (DS) and FFR in both groups, although this was significantly stronger in the AS + CAD than in the CAD alone group (R = −0.63 vs −0.44, p <0.01). Likewise, the correlation between minimum lumen diameter and FFR was stronger in the AS + CAD than in the CAD alone group (R = −0.54 vs −0.41, p = 0.05). Receiver operator characteristic curves analysis showed that DS was a better predictor of hemodynamically significant coronary stenoses (FFR ≤0.8) in the AS + CAD rather than in the CAD alone group (area under the curve = 0.83 vs 0.67, p <0.01). With 50% DS cut-off value, the sensitivity, specificity, and accuracy was 77%, 66%, and 70% in the AS + CAD group versus 59%, 63%, and 61% in the CAD alone group. In both groups, the diagnostic accuracy of DS in predicting FFR was higher in the right and circumflex coronary artery compared with the left anterior descending artery (LAD), although this was only statistically significant in the AS + CAD group (area under the curve 0.88 in the right and circumflex coronary artery vs 0.76 in LAD, p = 0.03). In conclusion, the correlation between the angiographic and hemodynamic significance of coronary stenoses is modest in AS patients. The assessment of CAD severity solely based on angiography poorly predicts the hemodynamic significance of the coronary stenosis especially when these are located in the LAD.