Background Intraoperative penile erections following the initiation of either regional or general anaesthesia is rare; however, when it occurs in patients undergoing urologic procedures it may delay, or even cancel the planned surgery. The aetiology is unclear. Various treatments proposed for producing detumescence are not always effective. Use of intracavernous alpha-adrenergic agonists is an efficient and rapid but short-lasting treatment. Furthermore, repeated intracavernous injections of vasoactive drugs may be harmful. Dexmedetomidine is a potent, selective alpha(2)-adrenoreceptor agonist. In our study, we evaluated the effect of dexmedetomidine on intraoperative penile erection.