Nonepithelial tumors of the urinary bladder are rare and among these benign tumors are far more rare. A case of leiomyoma of the urinary bladder is reported. A male patient, aged 59 years, was admitted to our hospital with complaints of dysuria and marked hematuria. Cystoscopic examination revealed a ball shaped tumor, pigeon egg in size, with normal mucosal covering, located on the right side of the bladder neck. Urethrocystography revealed a filling defect by the tumor. This was diagnosed preoperatively as a benign mesenchymal tumor, and was removed by cystotomy. The tumor was yellowgreyish macroscopically, weighed 20gm., measured 3.8×3.5×3.0cm, and was diagnosed pathohistologically as a leiomyoma. This is the 36th reported case in Japanese literature.
