This work aimed to study role of sympathetic over activity as a possible mechanism of Psychogenic Erectile Dysfuntion. Fifty subjects were divided into two groups, group A included 30 patients with Psychogenic Erectile Dysfunction as estimated by normal clinical response to Intracavernosal injection test and RigiScan monitoring, group B included 20 subjects with normal erectile function.The 24 hour urine have been collected for each subject in both groups.The VMA level was measured. There was no significant difference in the level of VMA between both groups, P>0.05.