Most rhabdomyosarcomas (RMSs) of the female genital tract occur in infants and young children as sarcoma botryoides. Vaginal RMS occurring in a postmenopausal woman is extremely rare. To our knowledge, only three vaginal RMSs have been reported in patients who were over 50 years of age. Herein, the first case in Taiwan and the fourth case in the world is reported, and the pertinent literature is briefly reviewed. A 63-year-old woman complained of a few days of abnormal vaginal bleeding. Vaginal examination demonstrated two black polypoid tumors located at the left-lateral and posterior wall of the vagina. The patient had previously undergone a vaginal total hysterectomy for rectocele and urine incontinence, so surgical treatment including local wide excision and bilateral salpingo-oophorectomy were performed under the diagnosis of malignant vaginal tumor. The clinical, histopathological, and immunohistochemical studies revealed a group Ia pleomorphic RMS. Postoperative radiotherapy was performed. The patient remains alive and well 12 months after a combined therapy.