Introduction: Posterior Capsular Opacification (PCO) is a common condition that can occur months or even years after cataract surgery. The standard treatment is a laser procedure called Nd:YAG laser capsulotomy. Although effective, it may cause side effects such as increased eye pressure, swelling in the retina (cystoid macular oedema), damage to the corneal cells, retinal detachment, and marks on the intraocular lens (IOL). Aim: This study aimed to examine how the corneal endothelial cells are affected before and after Nd:YAG laser capsulotomy in patients with PCO, using a test called specular microscopy. Materials and Methods: This was a prospective observational study conducted at Pacific Medical College, Udaipur, India. It included 50 eyes from 50 patients with PCO, carried out between January and April 2025. All patients received Nd:YAG laser treatment in the affected eye and were checked again after one week and one month. Specular microscopy was used to measure Endothelial Cell Density (ECD), Coefficient of Variation (CV), and the percentage of hexagonal cells (hexagonality). Data was analyzed using SPSS version 26.0, with Chi-square and ANOVA tests to check for significance. Results: After one week, 90% of patients (45 out of 50) had a Best Corrected Visual Acuity (BCVA) better than 6/18, and after one month, 94% (47 patients) had BCVA of 6/18 or better. The average ECD before the laser was 2356.76 cells/mm². This dropped to 2231.8 cells/mm² after one week and 2199.2 cells/mm² after one month. The reduction in ECD at one month (157.56 cells/mm²) was statistically significant (p < 0.0001). Conclusion: Nd:YAG laser capsulotomy is a safe, effective, and non-invasive procedure for managing Posterior Capsular Opacification. However, it can lead to structural and functional changes in the corneal endothelial cells.