Angiography of the ileopudendal vascular tree was performed for the evaluation of impotence in 73 patients. This technique proved useful in identifying those cases caused by vascular lesions in major arteries and small penile vessels. Organic diseases cause a much higher proportion of impotence than in generally suspected, with vascular occlusions causing the greatest number of cases. Nocturnal penile tumescence (NPT) studies are the best screening procedure in the author's view. In this series, NPT was followed by angiography, which provided the definitive diagnosis.