The aim of this work is to evaluate the effect of repeated intracavernosal self injection on the peak systolic velocity and the diameter of cavernosal arteries using pharmacopenile duplex ultrasonography (PPDU).This study was carried out on thirty patients complaining of erectile dysfunction recruited from Andrology clinic, Kasr El Aini hospital, Cairo University who were positive responders to intracavernosal injection, their age ranged between 32 and 65 years, nine of them were smokers, eleven of them were diabetic, twenty four of them received bimix and seven received quadmix for IC self injection.Duplex evaluation was performed to the patients on self injection therapy for comparison of peak systolic velocity and cavernosal artery diameter before and after finishing the ten doses of IC self injection.According to color duplex ultrasonography, there was significant increase in the diameter and peak flow velocity of the cavernosal arteries after ten doses of repeated IC self injection therapy in comparison to it before starting the treatment course.