Erectile dysfunction is an important problem for men and their families which has an organic cause in about 50 percent of cases. When there is a vasculogenic etiology for this defect, radiologic assessment is unavoidable. Cavernosometry and Cavernosography are ultimate procedures for diagnosis of venous leakage. There is no reliable data about this defects in Iran. The objective of this study was to determine the rate of venous leakage in patients with erectile dysfunction by Pharmarco-Cavernosometry and Cavernosography. In this case series study, 100 patient with erectile dysfunction who referred to radiologic ward in Sina hospital was selected and Pharmarco-Cavernosometry and Cavernosography were conducted for them. In Cavernosometry, after injection of Prostaglandin E1 and salin normal infusion into corpus covernosum, the pressure was determined. In cavernosography, diluted omnipaque was injected and venous leakage and other defects were recognized. Myoclinic's criteria was use for analysis of the results. Mean age of patients was 35.6±11.6. Most of the cases were in 20 to 40 age group. The frequency of venous leakage based on 50 mmHg reduction in pressure (from 150 mmHg), after 30 seconds discountinuance of normal salin infusion was 90 percent. This figure based on the ratio of Maintenance Flow Rate to Induced Flow Rate, was more than 92 percent. The frequency of venous leakage according to Cavernosography was 89 percent. There was no significant side effects in any of cases induced by procedures. The results of study, shows the high prevalence of venous leakage in patients referring for erectile dysfunction.