Dobutamine echocardiography (DE) and rest-redistribution Thallium-201 (TI) scintigraphy are promising techniques in the evaluation of myocardial hibernation. To assess the comparative accuracy of both modalities in the prediction of recovery of function following revascularization, 14 patients with chronic stable coronary artery disease and regional dysfunction underwent DE, rest and 4h redistribution TI tomography prior to, and late 16-8 wks) following coronaryangioplasty. Low and high dobutamine doses were used (2.5 up to 40 μg/kg/min). A 13 segment-LV model was used for analysis of both, quantitative TI tomograms and semiquantitative wall motion score (6 grades; hyperkinesia = 0 to dyskinesia = 5). Serial resting echocardiograms were digitized and randomized on a quad-screen. Of 182 segments, 91 had abnormal wall motion of which 54 were revascularized. Seventeen of the 54 revascularized segments (31%) exhibited significant recovery of function ( ≥ 2 grade improvement) at late follow-up. In contrast, of the 37 dysfunctional segments not revascularized, none had improvement in function. In these unrevascularized dysfunctional segments, resting TI uptake was unchanged from preto late post angioplasty (68% vs 63%, P = NS). However, in revascularized segments, a significant improvement in TI uptake was observed, the most pronounced being in segments showing recovery of function (72% to 89%, P = 0.0002, n = 17). Criteria for prediction of recovery of function were, for DE, the presence of biphasic response (augmentation at low dose and worsening at peak dose) and for TI, a resting uptake ≥ 60% or an increase to ≥ 60% upon redistribution). The sensitivity for prediction of recovery of function of individual segments was 94% for DE and 100% for TI tomography with a specificity of 84% for DE and 53% for TI. In false positive segments by TI (n = 18), resting uptake was unchanged after angioplasty (78% vs 83%, P = NS). Analysis by patients showed similar findings: both DE and TI tomography were 100% sensitive with a specificity of 78% and 63%, respectively. Dobutamine echocardiography and rest-redistribution TI tomography are therefore helpful in the assessment of myocardial hibernation. While both tests have similar sensitivity, dobutamine echocardiography appears to have a higher specificity for predicting significant recovery of systolic function following revascularization.