Arteriographically determined occlusive disease within the hypogastric-cavernous bed in impotent patients following blunt perineal and pelvic trauma. To determine the presence, location and pattern of arterial occlusive disease within the hypogastric-cavernous arterial bed in impotent men following blunt perineal and pelvic trauma, we reviewed the selective internal pudendal arteriograms of 20 patients with a history of blunt perineal and 7 with blunt pelvic trauma who had immediate development of impotence. Arteriographic studies of 104 other impotent patients also were reviewed and compared. Patients with persistent impotence immediately after blunt pelvic and perineal trauma had significantly different patterns of arteriographically demonstrated occlusive disease within the distal hypogastric-cavernous arterial bed consistent with the site of the traumatic injury. Those who sustained blunt pelvic trauma and complained of immediate impotence revealed arterial occlusive lesions mainly in the internal pudendal, common penile, cavernous and dorsal arteries. The incidence of arterial lesions in the distal internal pudendal or common penile artery was significantly higher (p less than 0.01) in patients with blunt pelvic trauma (92%) than in those with blunt perineal trauma (35%). Patients who sustained blunt perineal trauma and complained of immediate impotence demonstrated a more focal pattern of pathological arterial occlusion primarily in the cavernous and dorsal arteries. The incidence of a solitary arterial lesion in the cavernous artery without proximal disease was significantly higher (p less than 0.05) in patients with blunt perineal trauma (48%) than in those with blunt pelvic trauma (8%). It is hypothesized that blunt trauma without immediate impotence may be a potential risk factor for later development of arterial vasculogenic impotence, and that unrecognized or seemingly innocuous trauma may be a factor in cases of idiopathic impotence. Patients without trauma and with vascular risk factors have a more diffuse pattern of arteriographically demonstrated arterial lesions. 