Gastric polyps encompass a wide variety of lesions that most commonly arise from the gastric epithelium. However, coincidental gastric carcinomas have rarely been reported, being found in only 2~3% of patients with hyperplastic polyps. A 68-year-old male was admitted to our hospital for bleeding control of a gastric polyp. The gastroscopy shows numerous polyps in the entire gastric mucosa and a huge ulcer with bleeding. The bleeding of the gastric ulcer could not be controlled by gastroscopic procedures. So, we performed total gastrectomy for bleeding control. The pathologic findings shows poorly differentiated adenocarcinoma with hyperplastic polyps. We performed treatment with Cisplatin and 5-FU for two cycles. Two months postoperative, he was admitted due to dyspnea associated with ascites. We performed a ckeckup by computer tomography. It revealed cancer recurrence with lymphatic and liver metastasis, and diffuse massive ascites with mesenteric cake, and it suggested cancer peritonei.