Introduction: Sarcomatoid carcinoma describes a biphasic malignancy with features of epithelial and mesenchymal differentiation. It rarely occurs at the urinary bladder but is usually aggressive and associated with poor prognosis. Case Presentation: We here report a case of sarcomatoid carcinoma of the urinary bladder of a 48 years old man with intermittent painless haematuria over an 18-month period. Imaging examination showed intraluminal protrusion of a tumour on the right posterior wall of the bladder. Diagnosis: The patient was initially diagnosed as a right bladder mass. Interventions: The patient underwent two rounds of transurethral resection of bladder tumour (TURBT) and pathological analysis suggested the tumours were invasive urothelial carcinomas. Radical cystectomy was later performed, and pathological analysis suggested a stage T4 sarcomatoid carcinoma. The patient received 5 cycles of gemcitabine and cisplatin. Outcome: The patient died of multiple organ dysfunction syndrome 8.5 months after the diagnosis of sarcomatoid carcinoma. Conclusion: Sarcomatoid carcinoma of the urinary bladder is a highly malignant disease, and the histopathological characteristics are distinct. The diagnosis, surgical management, and chemotherapy of this patient are discussed together with previous cases reported in the literature