The questionnaire survey was conducted on treatment strategies for gastric cancer with peritoneal dissemination at 7 institutions, including 5 designated cancer hospitals in Yamaguchi prefecture. Staging laparotomy was performed at 6 out of 7 institutions. Six out of 7 institutions selected the treatment strategy for P0CY1 cases", upfront resection and adjuvant therapy". The doublet chemotherapy was performed by S-1 plus platinum or taxane. Surgical treatment for P1 cases, conversion gastrectomy was considered at all institutions when it was judged that R0 resection was possible after induction chemotherapy. Chemotherapy for P1 cases was treated according to the guidelines at all institutions, and the regimen was not changed depending on the peritoneal dissemination.