There are still controversies about the mechanism of penile erection. Arterial aspects of impotence have received considerable attention, but just recently the venous component became widely recognized. Twenty patients with abnormal cavernosometry (flow rate over 280 mL/min) and no rigid erections (intracavernosal pressure lower than 80 mm Hg) were analyzed. Surgical ligation of the dorsal veins was performed in 12 cases, 9 of which also required ligation of the crus of each corpus cavernosum. After these ligations, erection improved sufficiently to allow satisfactory intercourse in 9 of 12 patients. Two patients became impotent after eight months of normal sexual performance. The 3 failures showed persistently high flow rates and one leakage by the crural edge which had not been ligated at surgery. In selected patients with organic impotence the venous abnormalities should be assessed routinely and dorsal veins and the crural edge of the corpus cavernosum should be ligated in an attempt to restore erectile function.3535-7