We report a case of a 44-year-old woman who had coexisting distinct and separate primary tumors of the bladder: a leiomyosarcoma and a transitional cell carcinoma (urothelial cancer). The patient presented with macroscopic hematuria. A computed tomography scan of the pelvis showed a bladder mass along the left anterolateral wall. A transurethral resection of the bladder was performed. A pathological examination revealed that the mass was leiomyosarcoma. The patient underwent radical cystectomy with ileal conduit diversion. The urinary cystectomy specimen revealed an 11 cm x 6 cm x 5 cm solid mass on the left anterolateral wall and two 1-cm papillary tumors with different localization on the right and left lateral walls of the urinary bladder. Pathological examination revealed that the masses were high-grade leiomyosarcoma and urothelial cancer. Because of the differences in the histogenesis and prognosis, such cases should be differentiated from cases of carcinosarcoma of the urinary bladder. Synchronous occurrence of urothelial cancer and sarcoma as two separate primary tumors in the bladder is very rare. To our knowledge, seven cases of coexisting sarcoma and transitional cell carcinoma of the urinary bladder have been reported in the literature.