A 74-year-old female was referred to our hospital for non-muscle invasive bladder tumors initially treated at another hospital. Preoperatively, computed tomography and magnetic resonance imaging demonstrated non-muscle invasive bladder tumors and a vaginal tumor. A second transurethral resection of the bladder tumors, transvaginal tumor resection, and systemic chemotherapy were performed. The histopathological appearances of both tumors were very similar and the diagnoses were urothelial carcinoma (UC). The pathogenesis of the vaginal UC was considered to be the primary UC or metastasis from the bladder UC. Vaginal UC is extremely rare and this is only the 15th report in the literature.