Abstract: Objective: To evaluate the clinical and pathological features of bladder carcinosarcoma and its diagnosis and treatment. Methods: The clinical data from 3 patients with bladder carcinosarcoma treated from January 2002 to September 2006 were analyzed and the related literatures were reviewed. Results: The 3 cases were all male and the age was 60, 36 and 13 years old, respectively. The most common symptoms were painless gross hematuria or pollakisuria. Bultrasound or CT showed masses of the bladder. Cystoscopy showed bladder tumor in 1 patient. Partial resection was performed in 2 patients. Radical cystectomy and pelvic lymph node dissection were performed in 1 patient. Chemotherapy was given to 2 patients after surgery. Pathological examination revealed that the tumors were composed of epithelium and mesenchyme and were diagnosed as bladder carcinosarcoma. Immunohistochemistry showed positive expression of Myo and negative expression of CK, LCA, CD20, CD45Ro, NSE, CgA, Syn, Vim and Des in tumor tissues of 1 patient and positive expression of Vim, CD68 and CK and negative expression of Des, Actin, S-100, MyoD1, Myogenin and SMA in another patient's tumor tissues. One patient died of lung and liver metastasis 30 months after surgery, another died of lung metastasis 8 months after surgery and the other one was failed to be followed-up. Conclusion: Bladder carcinosarcoma is a rare malignant tumor, with high malignancy, strong ability to infiltrate, rapid progression and poor prognosis. The diagnosis depends on pathology and immunohistochemistry. Early radical cystectomy is the best treatment.