Abstract: Breast cancer, one of the most common female malignant tumours, mostly metastasizes to the bone, liver and lung. The case of gastric metastasis of breast cancer is relatively rare, and the differentiation of breast cancer from primary gastric cancer is also a major difficulty in clinical practice. In this paper, we report a rare case of gastric metastasis from breast cancer, which was diagnosed as metastatic invasive gastric adenocarcinoma originating from lobular carcinoma of the breast according to the immunohistochemical results of the patient, combined with the patient's medical history. The patient was given fulvestrant injection combined with abecycline for endocrine therapy against tumour after endoscopic mucosal dissection, and the prognosis was good. The clinical manifestations, diagnosis and treatment of this disease are discussed through relevant literature review, with the aim of providing reference for the clinical diagnosis and treatment of gastric metastasis of breast cancer.