AIM: To assess the corneal biometric parameters and endothelial cell characteristics in microcornea patients, and exploring their correlations. METHODS: This cross-sectional study included 28 patients of microcornea with uveal coloboma (MCUC), 13 patients of microcornea without coloboma (MCNC), and 30 age-matched healthy individuals (the control group). Corneal biometric parameters such as axial length (AL), anterior chamber depth (ACD), and white-to-white corneal diameter (WTW) were measured using the IOL Master. The corneal endothelial cell density (ECD), percentage of hexagonal cells (6A), average cell area (AVE), maximum cell area (MAX), minimum cell area (MIN), cell area standard deviation (SD), and coefficient of variation (CV) were collected by specular microscopy. RESULTS: This study included MCUC and MCNC patients with age- and sex-matched controls. All patients exhibited significantly reduced WTW (MCUC: 8.51±0.71 mm; MCNC: 9.08±0.42 mm) and worse logMAR BCVA (MCUC 0.62±0.43; MCNC 0.46±0.28) compared to controls (both P<0.001). The ECD was 3106.32±336.80 cells/mm² in the MCUC group and 2906.92±323.53 cells/mm² in the MCNC group, both significantly higher than the control group (2647.43±203.06 cells/mm², P<0.05). In contrast, the CV, AVE, SD, and ACD in the MCUC and MCNC groups were significantly lower compared to controls (P<0.01). In patients with microcornea, the WTW was negatively correlated with the ECD and 6A, but positively with the CV, MAX, AVE, and SD. The ACD was negatively linked to the ECD, but positively to the AVE. CONCLUSION: The corneal ECD and 6A are increased, while the CV is decreased in patients with microcornea, particularly in those accompanied by uveal coloboma. The ECD and morphology demonstrate close correlations with the WTW and ACD.