Abstract Background: Phacoemulsification which is performed through a limited space (anterior chamber of the eye) carries the risk of endothelial cell loss (ECL). So, the aim of this study was to compare the loss of corneal endothelial cells after phacoemulsification according to different anterior chamber depths in hard cataract. Aim of Study: Compare the loss of corneal endothelial cells after phacoemulsification according to different anterior chamber depths. Differences in cumulative dissipated energy, Endothelial cell loss among the anterior chamber depth groups. Patients and Methods: Prospective study on 30 eyes of 25 patients with senile cataract of nuclear opalescence grade 3 (NO3) divided into 2 groups according to anterior chamber depth: group A >2.99mm & group B < OR=2.99mm. intraop-erative mean cumulative dissipated energy (MCDE) and the used irrigation solution volume were measured. Clinical examination and investigation include Best Corrected Distance Visual Acuity and Endothelial cell count (ECC) that measured preoperative, one week and 2 months postoperative. Results: No statistical significant difference between the two groups in MCDE and irrigation solution volume. Preop-erative ECC was statistical significant higher in group A than B and become highly statistical significant higher in group A than B 1 week and 2 months postoperative. ECL was statistical significant higher in group B than A 1 week and 2 months postoperative. In each group there was high statistical signif-icant improvement in best corrected visual acquity 1 week and 2 month postoperative. Conclusion: The current study concluded that shallow anterior chamber depth is a risk factor for endothelial cell loss in hard cataract (NO3) in phacoemulsification cataract surgery. So, surgeons should pay more care in patient with shallow anterior chamber depth with hard cataract densities.