A thorough diagnostic evaluation was done on 27 impotent men. In addition to a detailed history and physical examination each patient underwent a psychiatric interview, Doppler penile blood pressure determination and measurement of the bulbocavernosus reflex latency time. Abnormalities in penile blood pressure were detected in 67 per cent of the patients, neurologic abnormalities were found in 41 per cent and psychiatric disorders were noted in 35 per cent. Of the 27 patients 48 per cent had a combination of neurologic, psychiatric and vascular abnormalities. A definite cause-and-effect relationship between these abnormalities and impotence has not been established.