Metastatic tumors in the breast are quite rare and constitute 0.5 to 6% of all breast malignancies. They often occur in a polymetastatic context. The most frequent primitive tumors are lymphoma, leukaemia and malignant melanoma. The gastric origin is seldom reported. We report here the observation of a 40-years woman operated in urgency for an acute abdominal syndrome. A gastric tumor was discovered intraoperatively with ovarian metastasis and peritoneal carcinosis. The pathological examination revealed a gastric signet ring cell carcinoma with an infiltration of the right ovary. Four months later, the patient presented with a lump of the right breast. The histologic examination corresponded to a mammary metastasis by a signet ring cell carcinoma from stomach. The objective of our work is to discuss through this observation the anatomoclinical and evolutionary characteristics of breast metastasis.