Mesenchymal tumors of the urinary bladder are rare, and the majority of them are malignant. We report a case of leiomyoma of the urinary bladder presenting with symptoms of voiding dysfunction. We performed surgical resection of the leiomyoma and repair of the bladder. Small capacity of the bladder with right vesicoureteral reflux was noted in outpatient department follow-up. A review of the relevant literature is also provided.