Breast metastases from gastric cancer are extremely rare. A case report of a 37-year-old female with breast inflammatory invasion and ascites is described. Breast biopsy revealed carcinomatous invasion of the lymphatics from adenocarcinoma cells with signet-ring features. Estrogen (ER) and progesterone receptors (PR) and c-erb-B2 were negative. Upper gastrointestinal endoscopy revealed a prepyloric ulcerative mass. Histopathologic examination of the lesion showed infiltration from a high-grade adenocarcinoma, identical with that of the breast. Immunostaining was positive for cytokeratins CK-7 and CK-20 and CEA and negative for ER and PR. Ascitic fluid cytology was positive for adenocarcinoma cells. Mammography was not diagnostic. Abdominal CT scanning revealed large ovarian masses suggestive of metastases (Krukenberg's tumor). A cisplatin-based regimen was given but no objective response was observed. The patient died six months after initial diagnosis. A review of the literature is performed.