The authors report a case of metastases of breast cancer confined to the uterus and cervical subserous leiomyoma in a postmenopausal woman under tamoxifen therapy for two years. After abnormal uterine bleeding, pathologic examination on biopsy of a cervical polyp revealed cervical involvement secondary to lobular breast cancer. The patient underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy. Pathologic examination of the surgical specimen revealed both invasion of breast origin and of the cervix until the isthmus, endometrium and cervical subserous leiomyoma. The adnexa uteri were not affected. The possibility of uterine metastases in patients suffering from breast cancer, either undergoing tamoxifen therapy or not, always has to be considered.