Although there has been a marked decline in mortality due to coronary artery disease (CAD) in the overall population in the past three decades, reducing CAD mortality in patients with diabetes has proven exceptionally difficult. Several epidemiological studies have shown that diabetes is associated with a marked increase in the risk of CAD. The symptoms are not a reliable means of identifying patients at higher risk considering that angina is threefold less common in diabetics than in nondiabetics. The increasing prevalence of diabetes and the associated high cardiac risk raised the question as to the need to develop approaches to identify the diabetic patients at the highest risk of CAD. Stress myocardial perfusion single-photon emission computed tomography has taken a central role in the diagnosis, evaluation, and management of CAD in diabetic patients. This review focuses on the prognostic value of cardiac radionuclide imaging in asymptomatic diabetic patients.