Intramedullary spinal cord metastasis(ISCM)is rare. However, with advances in diagnostic imaging, the incidence of ISCM is increasing. We herein present a case of breast cancer metastasis in the lower thoracic spinal intramedullary area in a patient who was then successfully treated with emergency radiotherapy. A 56‒year‒old woman with breast cancer was admitted to our hospital due to rapidly progressing weakness in both legs and bladder and rectal disturbance. Spinal MRI revealed a gadolinium‒enhancing intramedullary lesion. The patient was treated with emergency radiotherapy and oral steroids. Although the prognosis of ISCM is extremely poor, emergency radiotherapy could be an effective treatment for ISCM to improve the patient's quality of life(QOL).