The clinical case of a 73-year-old man with a history of transitional cell carcinoma of the bladder, an ulcerated mass on the left hemitrigone and left hydronephrosis who underwent radical cystoprostatectomy and urinary diversion followed by cisplatin-gemcitabine chemotherapy is presented. Pathological examination revealed a biphasic mixed tumor characterized by an epithelial and a mesenchymal component. At 24 months of follow-up the patient is alive and free from recurrent disease, with good quality of life and preserved renal function. Carcinosarcoma is highly aggressive and often has a dismal outcome regardless of treatment. Among all the studied prognostic factors, pathological stage is the main predictor of survival. The outcome of our patient suggests that the relatively well tolerated gemcitabine-cisplatin regimen after surgical treatment of invasive carcinosarcoma of the bladder might improve the currently dismal prognosis of selected elderly patients.