A 40-year-old man with dysuria was referred to our department on November, 18, 2004. A transabdominal ultrasonography revealed a cystic mass arising from his bladder neck. Computed tomography and magnetic resonance imaging revealed the cyst to be homogeneous and ovally shaped with a clear margin. Bilateral vasography showed the compression of the left seminal vesicle by the cyst and there was communication between the cyst and the left seminal vesicle for diagnosis of the seminal vesicle cyst, percutaneous needle aspiration was performed. The aspirated fluid included microscopical spermatozoa and proved negative for cytology. Absolute ethanol was injected into the cyst and transurethral unroofing of the cyst was performed on January 14, 2005. The prostate was resected until we reached into the cyst.