for over 3 years. A 67-year-old woman underwent distal gastrectomy for advanced gastric cancer. Histological examination of several nodules in the posterior gastric wall led to suspicion of peritoneal dissemination. Low-dose FP treatment was performed for only 5 days after surgery. Peritoneal dissemination was diagnosed at the time of surgery for postoperative abdominal hernia 20 months after the gastrectomy. TS-1 was administered postoperatively, and recurrence or progression has not been detected for 3 years 4 months. Another patient, a 68-year-old woman,underwent distal gastrectomy for advanced gastric cancer with multiple lymph node metastasis and peritoneal dissemination. TS-1 was administered after surgery, and no recurrence or progression has been detected for 3 years and 7 months. These cases suggest that TS-1 is a promising treatment for gastric cancer with peritoneal dissemination.