We describe a 61-year-old woman with diabetes insipidus caused by a pituitary stalk metastasis from breast cancer. She had a medical history of breast conservation therapy for early breast cancer 5 years previously. Pituitary, lung, liver, bone and neck lymphnode metastases was revealed at the same time. She received systemic chemotherapy consisting of docetaxel and cisplatin. After chemotherapy MRI finding in pituitary gland was improved, lung and liver metastases also improved, however, symptoms of diabetes insipidus did not improve. She is alive, receiving endocrine treatment for 2 years, since onset of diabetes insipidus.