The PET technique has been available for myocardial viability studies in Hungary since 1994. The early comparative results showed that FDG-PET identified more potentially reversible myocardial damages than [201Tl]-scintigraphy, defining the viability either by preserved metabolic activity of 50% or by metabolism-perfusion mismatch. According to the follow up of revascularized patients in our cases, FDG-PET had a positive predictive value for functional recovery at 80%. In our opinion, it is the detection of glucose metabolism that predicts with the greatest accuracy segments of hibernating myocardial tissue that will recover after revascularization. Unlike dobutamine echocardiography, PET can detect viable ventricular segments in the myocardium of lost contractile material often seen in the histological studies of chronically ischemic myocardium. The FDG-PET method can be regarded as the gold standard of myocardial viability.