Received August 20, 2005; revision received October 19, 2005; accepted October 25, 2005. Exercise ECG and stress imaging tests are used for diagnostic and prognostic purposes and to monitor the effects of therapeutic interventions.1,2 Such testing is most often applied to individuals with known or suspected coronary artery disease (CAD), and its value has been well studied.1 CAD is more severe, more prevalent, and occurs at a younger age in patients with diabetes mellitus (DM). Diabetic patients without known CAD have similar rates of subsequent myocardial infarction (MI) compared with nondiabetic patients with a previous MI.3 Accordingly, DM is considered a risk equivalent to established CAD, and national guidelines for treatment of cardiac risk factors recommend similar goals for diabetic patients and those with known CAD.4–8 Diabetic patients have significantly higher rates of silent ischemia than the general population, and it has been postulated that this contributes to more advanced CAD on initial presentation and worse outcomes in diabetic patients.9 Because of this altered natural history, investigators have evaluated stress testing and its diagnostic and prognostic value among patients with DM. In particular, the utility of stress testing among asymptomatic diabetic patients remains an area of active study. The following article seeks to review the diagnostic and prognostic value of exercise ECG and stress imaging tests in symptomatic and asymptomatic patients with DM. Additionally, it aims to identify gaps in the current literature and summarize what recommendations can be made from the available data. PubMed and Medline 1966 through June 2005 databases were searched to identify all studies that addressed stress testing primarily among patients with DM using the following keywords: diabetes mellitus, stress testing, coronary arteriosclerosis, myocardial infarction or ischemia, exercise test, predictive value of tests, or electrocardiography. References within each article were evaluated …