Background The corneal endothelium is a single layer of hexagonal cells that do not have the ability to regenerate. The normal density of corneal endothelial cells in adults is approximately 2500 cells/mm² and it is reduced by about 0.6% a year. The endothelium performs an essential function of maintaining the hydration of the cornea. When the endothelial cells density is reduced to approximately 800cells/mm², it may lead to corneal decompensation causing corneal edema and loss of corneal transparency which disrupts vision. Aim of the Work The aim of this study is to compare pre-operative corneal thickness between normal subjects and subjects with pseudo-exfoliation and to determine the effects of phaco-emulsification surgery on corneal endothelial cell density in cataract patients with pseudo-exfoliation syndrome. Patients and Methods The type of study was case controlled study, at department of Ophthalmology at Ain Shams University hospitals. This study included 66 patients divided to two equal groups (33 each): study group: 33 patients with pseudo-exfoliation, control group: 33 patients with senile cataract without pseudo-exfoliation. Results We found that ECD loss was 11.42% in the study group and 8.11% in the Control group 4 weeks after surgery. Phaco time and used BSS values were significantly higher in patients with PXS but had no significant influence on endothelial cell loss. They also suggested that the corneal endothelium in PXS be vulnerable to cataract surgery. Conclusion Torsional mode phacoemulsification and IOL implantation provided a safe and favorable surgical outcome in patients with/without PXS. Torsional phacoemulsification led to significantly higher ECD loss in the PXS than that in the control group during the whole follow up period.