Ejaculatory duct obstruction is thought to be a relatively uncommon but readily treatable cause of male infertility. Obstruction is frequently caused by cysts originating from or impinging on the ejaculatory ducts. The use of transrectal sonography has facilitated identification of patients with ejaculatory duct obstruction and has led to the realization that this abnormality is more common than was previously recognized. Transrectal sonography now plays a critical role in both the diagnosis and the treatment of this condition. The purpose of this pictorial essay is to illustrate the use of transrectal sonography in the diagnosis and treatment of ejaculatory duct obstruction.