The aim of this study was to assess the value of resting 99m Tc-Sestamibi scintigraphy for the detection of hibernating myocardium in zones of contractile dysfunction. Based on a series of 25 patients, 27 segments of supposedly hibernating myocardium were identified. All these segments corresponded to left ventricular wall motion abnormalities confirmed by contrast angiography and were perfused by a stenosed coronary artery: none of these zones were infarcted. Before revascularisation, comparison of the results of ventriculography and scintigraphy showed a correlation (p < 0.001) between the severity of regional contractile dysfunction appreciated by the center line method and the degree of myocardial hypofixation of 99m Tc MIBI. Three months after revascularisation, improvement of regional wall motion, assessed by control contrast angiography, was observed in 21 of the 27 segments studied (78%). Of these 21 segments, the viability of which was confirmed, 13 had a non-transmural uptake defect and 8 were normal on pre-revascularisation scintigraphy. The 6 segments without improvement at the 3 month control, had a transmural uptake defect on scintigraphy in 67% of cases. The authors concluded that when a residual uptake defect of 99m Tc sestamibi is present, viable myocardium may also be present.