We report a case of bladder leiomyosarcoma in a 27-year-old woman who had previously been treated with surgery and radiation for bilateral retinoblastoma. The patient was admitted to hospital with discomfort on micturition. Cystoscopy revealed a bladder tumor covered by normal urothelium. Transurethral resection of the bladder tumor was performed, and the histopathological diagnosis was leiomyosarcoma. Partial cystectomy was performed. The leiomyosarcoma of the bladder did not invade the muscle layer. However, bladder tumors recurred at new intravesical locations repeatedly. After transurethral resection of the bladder tumor had been performed twice, total cystectomy and creation of an ileal conduit were performed.