Purpose: The aim of this study was to evaluate nitroglycerine induced contractile reserve as detected by transthoracic echocardiography for determination of myocardial viability after acute anterior myocardial infarction and to compare the results with thallium-201 single photon emission computed tomography (Tl-201 SPECT) data taking post revascularization echocardiographic improvement as the gold standard for myocardial viability. Methods: Thirteen patients with acute myocardial infarction underwent transthoracic echocardiography with nitroglycerine infusion (0.4 - 2 mg/kg body weight per min.) and Tl-201 SPECT. Regional wall motion and regional thallium activity were analyzed by using a 16- segment model. At NE, on segments which have two or more contiguous dysfunction, determining at least one degree of wall motion recovery, was evaluated as viability. At Tl - 201 SPECT, on segments which have perfusion defect, identifying at least one degree of perfusion recovery was evaluated as viability. The wall motion score index (WMSI) was derived by summation of individual segment scores (1:normal; 4:dyskinetic) divided by the number of interpreted segments. Results: At baseline echocardiography, 75 myocardial segments were judged as dyssynergic. Regional wall motion improved by one grade or more during nitroglycerine infusion in 42(56%) segments. Tl-201 SPECT showed a reversible defect in 53 (70%) segments. After coronary revascularization, follow-up rest echocardiography showed the functional recovery in 57 (76%) myocardial segments. At both NE and follow-up rest echocardiography, WMSI decreased in according to baseline echocardiographic score index (p<0.05). At baseline echocardiography, NE and follow-up rest echocardiography, WMSI was 1.73±0.37, 1.51±0.22 and 1.44±0.31, respectively. When the functional recovery due to coronary revascularization was taken as a gold standard, it was observed that at segments level, the sensitivity of NE was 70% and specificity was 88%; the sensitivity of Tl-201 SPECT was 84% and specificity was 72%. Conclusions: In determination of myocardial viability after acute anterior myocardial infarction, we can say that NE is an alternative method to Tl-201 SPECT, and can be used in the medical centers without Tl-201 SPECT.