Small cell carcinoma (SCCB) of the bladder is rare and has a poor prognosis. Because of its rarity, gold standard care has not been established. The purpose of this study was to analyze the feasibility of a bladder-sparing approach. Data for treatments and outcomes in patients with a diagnosis of SCCB who received bladder-sparing treatment in our facility in the period from February 2007 to August 2012 were retrospectively analyzed. Six eligible patients received definitive radiotherapy in the cancer network of Tohoku region. Mean age of the patients was 69.5 years (range: 44 - 83 years), and median follow-up period was 29.2 months (range: 4.1 - 54.5 months). The mean dose was 60 Gy (range: 60 to 63 Gy), and 1.2 - 2.0 Gy was given per fraction. The initial CTV was the whole pelvis or the small pelvis, and it was shrunk to the bladder or tumor as a boost. The 1-year and 3-year overall survival rates were 83.3% and 55.6%, respectively. The 1-year and 3-year local control rates were both 80.0%. Only one patient had local failure. Recurrence or metastasis in sites other than the brain occurred in three (50%) of the patients after primary treatment. Two of those patients did not receive any chemotherapy. None of the patients had serious toxicities, and the bladder could be preserved in all patients. In this study, radiotherapy was effective for patients with SCCB. There was no recurrence in the bladder, and it was possible to preserve the bladder in all patients. Distant metastases were observed frequently, and chemotherapy was considered to be essential. Local treatment with radiotherapy has an important role from the point of view of the patient’s QOL.