The application of 18-F-fluorodeoxyglucose (FDG) imaging with single photon emission computed tomography (SPECT) to detect tissue viability has been introduced recently in several centers, both in Europe and the USA. This paper summarizes the available data on FDG SPECT. Three studies have performed a direct comparison between FDG SPECT and FDG PET, showing good agreement between these techniques. Preliminary data in patients with poor left ventricular function undergoing revascularization suggest that FDG SPECT can predict improvement of ventricular function after revascularization. Comparative studies between FDG SPECT and low-dose dobutamine echocardiography also showed close agreement. Although the initial results are promising, larger studies are needed to determine the precise role of FDG SPECT in the assessment of myocardial viability.