We obtained an objective evaluation of erectile function in patients with Peyronie's disease. Sexual dysfunction was analyzed in 222 patients with Peyronie's disease without previous local plaque therapy using a standardized protocol. Of the 222 patients 70 (31.5%) complained of not being able to perform intercourse. In 4 men (1.8%) standardized diagnostic procedure demonstrated only a severe angulation making coitus impossible, and in 3 men (1.4%) intercourse became unsatisfactory due to pain. Seven men (3.1%) reported distal penile flaccidity, including 4 in whom dynamic pharmacocavernosometry and pharmacocavernosography revealed veno-occlusive dysfunction. Of 56 men who complained of a complete loss of erection 51 did not respond to intracavernous pharmacological injection with prostaglandin E1, and 27 (48.2%) had abnormal arterial blood flow as shown by duplex sonography of the cavernous arteries, 47 (83.9%) had evidence of veno-occlusive dysfunction based on cavernosometric criteria and 33 (58.9%) also had cavernosographic evidence of the condition. Plaque associated venous drainage was evident in 15 of the 56 impotent patients (26.8%), equivalent to 45.5% of all cases with abnormal cavernosographic findings. Sexual dysfunction was evaluable in 31.5% of patients, and the main cause of impotence and loss of erection was veno-occlusive dysfunction.