Background: This study aimed to determine the influence of age on central corneal thickness and corneal endothelial morphology as well as to identify the relationship between them in normal Thai eyes.Methods: Non-contact specular microscopy was performed in volunteers stratified into seven age groups ranging from 11-88 years. The corneal endothelial parameters studied included central corneal thickness (CCT), endothelial cell density (ECD), coefficient of variation in cell size (CV), cell area (CA) and percentage of regular hexagonal cells.Results: In a total of 501 subjects (1002 eyes), the mean age was 43.12 ± 18.80 years and 347(69.3%) were females. The mean CCT, ECD, CV, CA, and hexagonality was 533.80 ± 33.00 μm, 2,732±258 cell/mm2, 37.61 ± 6.76%, 369.04 ± 37.90 mm, and 49.03% ± 7.53%, respectively. There was a statistically significant inverse correlation between age and CCT (r = -0.212, P <0.001), ECD (r = -0.484, P <0.001), and hexagonality (r = -0.193, P <0.001). The estimate rate of endothelial cell loss was 0.2% per year, whereas CV and CA had statistically significant correlation with age (r = 0.200, P <0.001 and r = 0.475, P <0.001). CCT correlated directly with ECD (r = 0.177, P <0.001).Conclusion: Normative data for corneal endothelial morphology in healthy Thai eyes showed that ECD, CCT, and hexagonality were significantly decreased, while CV and CA were increased with aging. The central corneal thickness was correlated with the endothelial cell density.