The findings of duplex doppler ultrasonography (DDU) of cavernous arteries (CA) and of dynamic infusion cavernosometry in 61 patients who underwent both diagnostic procedures were examined. Our work consisted in comparing the blood flow velocity in the CAs during the systolic peak, as measured with DDU, with the gradient CA occlusion pressure/mean brachial blood pressure and in attempting to determine whether there was a correlation between both measurements and whether patients were similarly classified by both methods. The results of each examination separately were also compared with the response to isolated injection of intracavernous drugs (ICI). Of the 61 patients, 56 were eligible for the study as 5 patients were excluded owing to a massive venous leak. A 78.6% of the patients were categorized similarly by both diagnostic methods. The correlation coefficient between both methods for the 56 evaluable patients was R = -0.756, implying a statistically significant correlation between the two measurements (p < 0.0001). The sensitivity, specificity and predictive value of a positive test as regards the response to the ICI of vasoactive drugs in both diagnostic methods showed very similar values in our sample. We conclude that both methods--the Doppler Ultrasonography and the measurement of the occlusion pressure of the cavernous arteries--are equally valid for assessing the arterial function of the cavernous bodies in erection. If we consider that the erectile function of the penis consists in storing energy in the form of pressure and that this pressure is supplied by the cavernous arteries, from a physiological point of view, it is more consistent to measure the pressure in these arteries.