Bladder leiomyoma is a rare benign mesenchymal tumor. This tumor is usually asymptomatic unless urinary tract function is affected. The symptoms include obstructive or irritative voiding symptoms, flank pain, and hematuria. Incontinence is an infrequent presentation. The treatment of bladder leiomyoma depends on the size and location of the tumor and often with favorable outcome. No malignant transformation has been reported. We describe a middle-aged woman of urinary incontinence resulting from a pelvic mass. Initially, the tumor was misinterpreted as an adnexal cyst. But the cystoscopy and computed tomography revealed an intramural tumor of the urinary bladder. We successfully treated the patient by enucleation of the tumor and restored her voiding function.