The patient was a 78-year-old man who underwent upper gastrointestinal endoscopy, revealing a sub-circumferential type 2 tumor in the lower body of the stomach. Histopathology revealed poorly differentiated adenocarcinoma. Computed tomography(CT)showed lymph node and liver metastasis(S6, S8), which corresponded to clinical Stage Ⅳ(cT4bcN2cM1 [HEP]). Five courses of XP therapy were administered for Stage Ⅳ disease. The sizes of the primary lesion and metastatic liver tumors were reduced, and a partial response was achieved. Distal gastrectomy and partial hepatectomy were performed. The resected specimen was diagnosed as ypT4b(transverse colon mesenteric), ypN0, ypM1(HEP). Thus, the final Stage was Ⅳ. During adjuvant chemotherapy with S-1, the para-aortic, left common iliac, and external peri-iliac lymph node metastases were detected by CT imaging 6 months after the operation. This prompted XP therapy resumption. The lymph node metastases worsened despite 2 additional XP courses. Progressive disease prompted the change in regimen to PTX plus RAM. After 7 courses, swollen lymph nodes were observed and CPT-11 was initiated. Since the disease continued to progress, nivolumab therapy was administered. The para-aortic, left common iliac, and external peri-iliac lymph nodes shrank after nivolumab initiation. The patient has responded well to nivolumab for more than 3 years without immunological adverse events.