The involvement of antihypertensive therapy in the pathology of hypertension associated male erectile dysfunction is unclear. Stroke prone spontaneously hypertensive rats (SHRSP) were treated chronically with the angiotensin converting enzyme (ACE) inhibitor captopril or placebo, normotensive rats served as controls. Mean arterial and intracavernosal pressure were measured during the induction of erection by autonomic ganglion stimulation. SHRSP-placebo treated rats were hypertensive and had a blunted erectile response. Captopril treatment returned both the blood pressure and erectile response to control levels. Therefore, ACE inhibitor therapy may not be responsible for the erectile dysfunction observed in treated hypertensive subjects.