In 37 patients 25 to 69 years old (mean age 49.6 years) with suspected 'vasculogenic erectile dysfunction', diagnosed on the basis of repeated negative reactions to intracavernous pharmacological stimulation, duplex Doppler measurements and pharmacocavernosometry were performed in one session under simultaneous pressure registration. A statistically significant difference between patients with and without veno-occlusive dysfunction was found by combining end-diastolic velocity and pressure in time. We conclude that color Doppler scanning in combination with simultaneous pressure registration can predict veno-occlusive dysfunction in 83-95% of the patients.