Metastatic breast involvement from extra-mammary neoplasms is unusual with a low incidence of 0.5% to 1.2% in clinical practice, 2.7% in cytological series, and 1.7% to 6.6% in autopsy series of all breast malignancies. Nearly 500 cases have been reported in small series and case reports. Gastric carcinoma rarely metastasizes to the breast. There are only 38 cases reported in PubMed. In this study, we present a case report of a 49-year-old woman who was diagnosed with right breast metastasis from a gastric carcinoma and undertake a literature review to pay attention to the diagnosis, treatment, and the prognosis of the disease.