The field of nuclear cardiology uses cardiac single photon emission computed tomography (SPECT) and cardiac positron emission tomography (PET) for diagnosis and evaluation of CAD patients. Hybrid cardiac imaging combining SPECT and PET with MPI is an externally promising noninvasive cardiac imaging tool which helps in the detection and quantification of hemodynamic obstructive CAD etc. the clinical application of SPECT myocardial perfusion imaging of CAD patients advocate treatment planning including strong family history and risk factors i.e., hypertension, diabetes, smoking etc., to assess borderline lesions in coronary angiography and follow-up of patients of coronary artery bypass graft, balloon angioplasty, thrombolytic therapy etc. Positron emission tomography (PET) myocardial perfusion imaging used for molecular diagnosis and assessment and include Tracers of Myocardial Perfusion, Rubidium-82 PET Myocardial Perfusion Study, Imaging of Rb-82, Myocardial Metabolism etc. This chapter also discuss about the emerging concepts for the diagnosis and evaluation of the CAD such as quantitation of myocardial blood flow, computation of myocardial blood flow with Rubidium-82 and comparison to N13 Ammonia, stress myocardial perfusion scan using F-18 Flurpiridaz and absolute quantification of myocardial blood flow etc.