Background: In certain conditions, there is a need for a specific and improved measure of cardiac performance. Routine methods for assessing left ventricular (LV) function are based on image-analysis or right heart monitoring which do not allow evaluation of ventriculo-arterial interaction. Chen et al presented a noninvasive method allowing measurement of end-systolic pressure–volume relation and its slope, the so-called end-systolic elastance (Ees), which is a major determinant of LV systolic performance and heart interaction with the systemic vasculature. Objective: To determine the normal values of LV elastance in infants and children based on Chen et al's method. Methods: The method involves measurement of the LV Ees using the equation Ees(sb) = [Pd–(End(est)×Ps×0.9]/[SV×End(est)] in 114 normal children: Group 1; 24 infants 1 to 12 months of age. Group2; 26 children aged between 1 and 5 years. Group3; 55 children 5 to 16 years of age and Group 4; 9 young adults aged between 16 and 20 years. Results: The mean±SD of the LV Ees in the 4 groups were 10.16± 4.7 mm Hg/ml for group 1, 5.44±1.36 for group 2, 3.29±0.94 for group 3, and 2.76±0.68 mm Hg/ml for group 4. Conclusion: There are significant inter-group differences which make the use of the provided normal values essential for assessment of LV function.