Erectile dysfunction has been explored as a condition secondary to elevated prolactin; however, the mechanisms by which elevated prolactin levels cause erectile dysfunction have not yet been clearly established. We here present a patient with a history of prolactinoma who suffered from persistent erectile dysfunction despite testosterone supplementation and pharmacological and surgical treatment for the prolactinoma. Patients who have had both prolactinemia and erectile dysfunction have been reported in the literature, but we find no report of a patient with persistent erectile dysfunction in the setting of testosterone supplementation and persistent hyperprolactinemia refractory to treatment. This case provides evidence supporting the idea that suppression of erectile function occurs in both the central and peripheral nervous systems independent of the hypothalamic-pituitary-gonadal axis.