A 9 1/2-year pharmaco-cavernosometry/pharmaco-cavernosography and pharmaco-arteriography study was performed in 131 men with persistent changes in erectile function following blunt pelvic or perineal trauma. The goal was to determine the incidence of hemodynamic impairment, and to characterize the location and pattern of abnormal venous drainage. Corporeal veno-occlusive dysfunction was identified in 62% of the cases and cavernous artery insufficiency in 70%. Pharmaco-cavernosography revealed abnormal venous drainage confined to the proximal corpora in 91% of the cases. Patients with pelvic trauma had significantly more abnormal sites of venous drainage (3 or more sites in 61%) and more severe degrees to which venous structures filled with contrast medium (23% had 3+ degree of luminal filling) than did patients with perineal trauma (61% had 1 or 2 sites of venous drainage and 92% had 1+ or 2+ degree of luminal filling). Pharmaco-arteriography revealed site specific arterial occlusive lesions consistent with the site of impact. Traumatic vasculogenic impotence is hypothesized as being the result of direct impact injury to the fixed proximal corpora and its arterial inflow bed. The exerted perineal impact force is estimated to range from 50 to 500 pounds, depending on the weight of the individual, height of the fall, speed at contact and surface hardness. Traumatic veno-occlusive dysfunction is theorized to be the consequence of focal intracavernous wound repair and permanent focal alterations in erectile tissue compliance. Traumatic vasculogenic impotence afflicts an estimated 600,000 American men of whom 250,000 have sports-related injuries. Future consideration should be given to the development of appropriate protective perineal equipment.