Postoperative endophthalmitis remains the most serious surgical complication and appropriate prophylaxis remains the mainstay of prevention.Normal conjunctival flora is proven to be the commonest organisms to cause postoperative endophthalmitis.The aim of this work is to compare the effect of vancomycin and povidone-iodine in eliminating these most common organisms causing potoperative endophthalmitis from the conjunctival sac preoperatively as a prophylaxis of postoperative endophthalmitis.This study is an experimental study made on 48 rabbits divided into 8 groups, in each group one organism is put in the conjunctival sac and either vancomycin or povidone-iodine is added and then measuring the amount of decrease in the organism colonies, and results are been compared.