Cases of bladder leiomyosarcoma represent 0.1% of all nonurothelial tumors. We present a case report of a 73-year-old man who underwent a radical cystoprostatectomy for a high-grade bladder leiomyosarcoma with an ileal diversion. The patient recovered uneventfully and no surgical margins were verified in final pathology. Early follow-up at 3 months shows no signs of computed tomography recurrence and adequate adaptation to ileal diversion. Although bladder sarcomas were once thought to have a grim prognosis, recent studies suggest that adequate surgical treatment is able to achieve optimal cancer control outcomes.