Small cell carcinomas of the urinary bladder originating from the neuroendocrine cells are extremely rare. We present a case of a 76-year-old patient with small cell carcinoma of the urinary bladder. The patient had hematuria and cystoscopy revealed a tumor located in a urinary bladder diverticulum. Partial resection of the bladder wall with diverticulectomy was performed. Microscopic examination established the diagnosis of neuroendocrine carcinoma, which was confirmed by immunohistochemistry. Three-month follow-up showed no recurrent disease. Patient refused further chemotherapy and radiotherapy.