The use of 18F-fluorodeoxyglucose (FDG) imaging with single photon emission computed tomography (SPECT) has been introduced recently to assess myocardial viability. Several centres have now gained experience with cardiac FDG SPECT imaging, and this report is a summary of the currently available FDG SPECT data. Three studies have compared FDG SPECT with FDG positron emission tomography and demonstrated good agreement between them. Initial results in patients undergoing revascularization suggest that FDG SPECT can predict improvement in contractile function after revascularization. Although the initial results are promising, larger studies are needed to determine the precise role of FDG SPECT in the assessment of myocardial viability.