Today coronary artery disease (CAD) is widely understood to constitute an advanced stage of atherosclerosis, an inflammatory pathology involving both coronary and extracoronary arteries. It is increasingly appreciated that perfusion imaging brings additional prognostic value as compared to morphological imaging alone, where myocardial perfusion abnormalities can be understood as the functional consequence of a broad range of present atherosclerotic vessel alterations, baring considerable significance for the diagnostic and prognostic work-up of CAD. Using recently introduced PET/CT hybrid scanners, the favorable characteristics of PET perfusion imaging and quantification can be further strengthened by adding CT morphological information, both components contributing to a comprehensive view on the heart and enabling combined morphological and functional imaging including three dimensional image fusion. Thus, cardiac PET/CT can provide both a reliable allocation of perfusion abnormalities to their supplying coronary artery and improved individual risk stratification for further clinical management.