The intracavemous pressure necessary to produce a passive erection was recorded in 35 patients suffering from impotence. Among these patients, 5 presented psychogenic impotence. The intracavemous pressure was also recorded at rest during inflow and in the state of erection. The 5 psychogenically impotent patients had passive erections with a flow of 80-120 ml/min. 18 patients suffering from organic impotence developed passive erections at a flow of 80-120 ml/min, while the remaining 12 men needed a flow between 160 and 300 ml/min with visualization of a venous leak. The intracavemous pressure varied between 90 and 110 mm Hg in the state of erection. Artificial erection, induced in impotent men, allows to classify patients with vascular organic impotence into three categories:those with pure arterial insufficiency; those with pure venous leak, and patients with both.