Cysts found on the ventral surface of the penis have been pathogenetically ascribed to defective embryologic closure of the median raphe,1-3 to anomalous developmental rests of the periurethral glands of Littre,3 and to the ectopic development of apocrine cystadenoma in the penile skin.4,5 This case reports a previously unrecognized but compelling pathogenesis for at least some ventral penile cysts, namely the anomalous congenital outgrowth of the entodermal urethral lining, giving rise to what is here designated as a urethroid cyst.