Background: Myopia, a form of refractive error, is a common pathologic change of the eye.  Objective: This study aimed to evaluate corneal endothelial cell density and morphological changes in moderate and high myopic eyes of children aged 6-15 years using specular microscopy. Methods: This prospective cross-sectional study included 80 eyes of Egyptian children aged 6-15 years divided into 3 groups, group I: 40 emmetropic, group II: 20 moderate myopic and group III:20 high myopic eyes. The endothelial cell parameters (endothelial cell density: ECD, hexagonality: Hex, coefficient of variation: CV and central corneal thickness: CTT) were measured by Topcon SP-1P specular microscope for all participants. Cycloplegic refraction, corneal curvature readings and axial length measurement were also assessed. Results:  This study found a statistically significant difference in corneal endothelial parameters in children with different refractive errors. It showed a reduction in endothelial density (ECD) values in the high myopic group (mean =3069.7 ± 372.8) compared to moderate myopic (mean =3146.7 ± 274.7) and emmetropic groups (mean =3343.5 ± 167.3). It also showed a decrease in hexagonality (HEX) and increase of coefficient of variation (CV) in high myopic (mean HEX =65.5 ± 8.2% & mean CV=26.8 ± 3.6% respectively) and moderate myopic (HEX=64.4 ± 4.1% & CV=26.6 ± 2.9%) groups compared to the emmetropic group (HEX=69.7 ± 4.5% & CV=24.1 ± 1.6%). Conclusion: There were significant changes in corneal endothelial morphology as myopic power increased. There were insignificant differences between high and moderate myopia groups as regards all corneal endothelial parameters. We described a normative endothelial cell parameters in Egyptian children aged 6-15 years that could serve as a valuable baseline for future reference.