Delineation of neural, arterial, and venous components contributing to penile erectile failure is critical to proper patient selection for surgical interventions, particularly for a subset of men with impotence as the sole manifestation of pelvic arterial disease. In addition to obtaining a history and physical examination specific for disordered erectile function and vascular risk factors, we developed a sequence of testing to include noninvasive estimates of penile perfusion, pulse volume recording (PVR), and penile/brachial blood pressure indices (PBPI); somatosensory evoked potentials from dorsal penile (PEP) and posterior tibial nerve stimulation (SEP) and bulbocavernosus reflex time (BCR); stimulation of artificial erection with injection of papaverine (AE); and selective hypogastric-pudendal arteriography with patients under epidural anesthesia, and corpus cavernosography with AE. Three hundred fifty-three men complaining of impotence were screened by PVR and PBPI; among these 42 impotent men and 20 additional concurrent potent control subjects had evoked potentials and BCR measurements, and 55 men received one or more AE injections. On the basis of these results, angiographic investigation was recommended. Age and risk factors were similar in the two groups. Abnormal penile blood perfusion was associated significantly only with cigarette smoking (p less than 0.0001) or overt large vessel disease. Impotent men with (138) or without perfusion abnormalities (215) averaged 54 and 56 years of age, respectively; impotent men with normal flow patterns most commonly had treated hypertension or diabetes (79 of 215 men). Covert neurologic abnormalities were detected in 28 of 42 impotent men. Abnormal penile perfusion plus failure of AE predicted isolated ischiopudendal trunk or pudendal artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)