Small intestinal metastasis is very rare. We encountered a case of intestinal metastasis from maxilla cancer causing preoperative peritonitis. A 63-year-old man had under gone surgery for maxilla cancer in December of 1997 at another hospital. He was admitted to our hospital because of nausea, vomiting, and abdominal pain in March of 1999. Peritonitis was obvious and a CT scan revealed free air, so an emergency operation was performed. During surgery, about 1000ml of dirty ascites containing pus was noted in the abdominal cavity, and ring stenosis of the ileum was noted in the ileum about 20cm to the oral side from the ileocecal region. Perforation was found in the ring stenosis, and an ileocecal resection was performed. Histopathological studies of the tumor revealed poorly differentiated squamous-cell carcinoma, the same pathological type as the maxilla cancer which had been operated on before. The postoperative course was uneventful, but a CT scan of the chest revealed lung metastasis. As to the metastatic course of maxilla cancer, we consider that maxilla cancer metastasizes to the small intestine through the chest mediastinum by lymphatic flow or blood flow. We suggest that in this case metastasis by blood flow because lung metastasis had occurred previously.