A 74-year-old man with bloody vomit was diagnosed as having clinical Stage Ⅳ advanced gastric cancer with lymph node metastasis around the abdominal aorta. Initially, for curative surgery, he was administered neoadjuvant chemotherapy. On day 32, in the second course of chemotherapy containing S-1 after 12 courses of chemotherapy containing S-1 and cisplatin, he developed pan-peritonitis owing to the perforation of gastric cancer caused by chemotherapy, and thus, we performed emergency omental implantation and peritoneal drainage. He was discharged from the hospital after 14 days with no trouble. His gastric cancer was judged to be resectable without retaining metastatic lymph nodes based on intraoperative findings and abdominal computed tomography. Therefore, 3 months after the emergency surgery, he underwent total gastrectomy with D1+(+No. 11d)lymphadenectomy. The postoperative course was uneventful. He rejected adjuvant chemotherapy despite our recommendation. Regrettably, intraabdominal dissemination was observed 15 months after total gastrectomy, and he then received chemotherapy again. He has remained alive for 57 months after the first visit to our hospital.