Objective To investigate the clinical value of dual-source CT in evaluating viable myocardium in patients with coronary heart disease. Methods A total of 42 patients with coronary heart disease diagnosed by coronary angiography in our hospital between September 2012 and December 2015 were retrospectively analyzed. All patients underwent dual-source CT and dual-isotopic myocardial SPECT imaging examination. Based on the results of dual-isotopic myocardial SPECT imaging examination, the sensitivity, specificity and accuracy of dual-source CT in the diagnosis of viable myocardium in patients with coronary heart disease were calculated. Results There were a total of 714 myocardial segments in 42 cases of patients. Based on the results of dualisotopic myocardial SPECT imaging examination, the sensitivity, specificity and accuracy of dual-source CT in the diagnosis of viable myocardium were 80.0% (120/150), 98.9% (549/555) and 93.7% (669/714) respectively. Compared with the SPECT imaging results, there were no significant differences (P<0.05). Conclusion The time and spatial resolutions of images of dual-source CT are high. Combined with first-pass perfusion and enhancement in delayed phase, the myocardial viability can be reliably determined. The diagnostic accuracy and the economy both are high, which can be used as the first choice to evaluate the myocardial viability in patients with coronary heart disease.