The patient is a 66-year-old male who underwent gastrojejunostomy at another hospital with the diagnosis of type 3 unresectable gastric cancer. He was admitted to our hospital for adjuvant chemotherapy. A CT scan revealed both peritoneal dissemination and a large tumor directly invading the pancreas and liver. After 7 courses of combined chemotherapy with 5-FU, Leucovorin, cis-platinum and methotrexate, an effective response, tumor reduction and the disappearance of peritoneal dissemination, was verified by CT scan. Pancreatoduodenectomy with transverse colectomy was carried out and the pathological diagnosis was also curative (pT3, pN1, pP0, HO: stage III A). Although he unfortunately died from peritoneal recurrence after 9 months, he maintained good quality of life after re-operation. We think this case shows the possibility of NAC for patients with far advanced gastric cancer with peritoneal dissemination to improve their prognosis or QOL.