Echocardiographic and radionuclide techniques are the most common techniques currently used to assess ventricular function. The aim of our study was to assess the performance of two well-known methods for analysis of gated myocardial perfusion with comparison to echocardiography in children. We analyzed the data from 64 children referred for myocardial perfusion scintigraphy. All underwent echocardiography and stress gated myocardial perfusion scintigraphy, except 5 who had only rest scintigraphy. We calculated the left ventricular volumes and ejection fractions. The parametric information from the echocardiographic reports was compared to the data obtained using gated myocardial perfusion. The reliability between the quantitative gated scintigraphy, the Emory cardiac toolbox, and echocardiography for end-diastolic and end-systolic volumes and ejection fractions in studies performed at rest were calculated at 0.85, 0.86 and 0.97, respectively using Cronbach's alpha coefficient. The values in stress studies were 0.83, 0.86 and 0.90, respectively. There was a high correlation, with r more than 0.88, between quantitative gated scintigraphy and the Emory cardiac toolbox for ejection fractions, and end-diastolic and end-systolic volumes, in studies performed both under stress and at rest. Weak correlation was observed between quantitative gated scintigraphy and the Emory cardiac toolbox compared to echocardiography, especially when considering ventricular volumes in stress studies. Although high correlation was observed between quantitative gated scintigraphy and the Emory cardiac toolbox, comparison with echocardiography showed poor agreement for both, meaning that scintigraphy is less suitable for assessing left ventricular volumes, and less reliable in assessment of ejection fractions. Echocardiography seems to remain the most widely used and reliable technique for this part of the diagnostic work up.