A substantial body of evidence documents the high diagnostic accuracy and prognostic power of cardiac nuclear imaging in the assessment of patients with suspected or known coronary artery disease (CAD). Myocardial perfusion scintigraphy (MPS) provides significant incremental information over and above that obtained by clinical and exercise electrocardiography variables. In patients with chronic CAD nuclear imaging has the ability to identify patients likely to benefit from revascularization from others in whom invasive treatment does not improve their prognosis. In patients presenting with chest pain in the emergency department, MPS can contribute substantially in the implementation of rapid-investigation protocols, allowing for timely management decisions and early discharge of low-risk individuals. In stabilized patients after an acute coronary event, MPS performed within a few days following the insult improves significantly risk stratification and facilitates the selection of the appropriate therapeutic strategy. In the setting of ischaemic left ventricular dysfunction, the presence of considerable amount of viable myocardium, as assessed by radionuclide imaging, is associated with improved survival, provided that these patients are submitted to revascularization. Beyond its clinical efficacy, MPS has also found to be very cost effective and has become integral part of numerous European and American guidelines.