This case involved a 69-year-old female patient with peritoneal dissemination of an advanced gastric cancer. She underwent chemotherapy comprisingintravenous and intraperitoneal paclitaxel combined with S-1. After 20 courses, a staging laparoscopy was performed, and pathological analysis of the peritoneal dissemination and cytologic analysis of ascites fluid yielded negative results. A radical robot-assisted total gastrectomy was successfully performed. The pathological stage was determined to be ypT4aN2M0, ypStage ⅢB. We continued to administer the same chemotherapy regimen for 15 courses (total: 35 courses)after surgery. No recurrence has been detected during the 1-year period after surgery.