Primary small cell carcinoma of the urinary tract is a relatively rare disease that is associated with a poor prognosis. The median overall survival time of patients with primary bladder disease is 19.6 month to 1.7 years, and that of patients with small cell carcinoma of the upper urinary tract is 15 months. Generally, curative surgery with chemotherapy according to the type of small cell lung carcinoma is a preferred treatment. However, standard treatment has not been established yet because the number of cases is small. We herein report the clinical features and outcome of four patients with primary small cell carcinoma of the urinary tract between 2007 and 2018 at our institution and review the literature.