A 69-year-old female had hormone therapy for liver metastasis after surgery for right breast cancer. She came to the hospital with a complaint of abdominal pain and was admitted with a diagnosis of small bowel obstruction. She had previously undergone surgery for an ovarian tumor and was suspected of having an intestinal obstruction caused by adhesions in her pelvis. She promptly improved with conservative treatment of fasting only. In the following months, she developed 2 intestinal obstructions, and CT scan revealed a neoplastic lesion in the small intestine. With the diagnosis of small intestinal tumor, laparoscopic surgery was performed. A neoplastic lesion was found in the ileum. A small bowel resection was performed. She was discharged with a good postoperative course. The pathological results showed breast cancer metastasis in the small intestine. Based on the diagnosis, postoperative chemotherapy has been started. Gastrointestinal metastasis of breast cancer is relatively rare and rarely causes clinical problems. We report a case of small intestinal metastasis of breast cancer.