Man's preoccupation with potency, or the lack thereof, has been present through the ages. Several documents still exist from which the clinical approaches of erectile dysfunction (ED) in medieval Persia can be ascertained. The medieval physicians described definitions and apparent causes of ED. They also noted hygienic and dietary rules as well as long lists of natural substances used in the treatment of ED. Many of the approaches of practitioners in medieval Persia are accurate and accepted even today; however, still more of them could be of use to modern medicine. The present review provides an overview of the knowledge of ED at the time.