Case 1 was a 78-year-old woman with a tumor in the stomach on preoperative CT of an inguinal hernia. The patient was diagnosed with advanced gastric cancer at posterior wall of fornix and underwent total gastrectomy and splenectomy. Postoperative pathological diagnosis was gastric mixed adenoneuroendocrine carcinoma(MANEC), T1b2, N1, M0, StageⅠB. She has been alive without recurrence for 3 years without postoperative adjuvant chemotherapy. Case 2 was a 78-year-old man who was admitted to the hospital with acute pancreatitis and had a thickened wall of the lesser curvature of the gastric antrum on CT. He was diagnosed with advanced gastric cancer and underwent distal gastrectomy and D2 dissection. Postoperative pathological diagnosis was gastric MANEC, T1b2, N1, M0, Stage ⅠB. Oral administration of S-1 was started as postoperative adjuvant chemotherapy, but he was very tired and ended in 1 course at his request. Computed tomography 6 months after the operation revealed multiple liver metastases, and he was transferred to best supportive care at his request. He died 1 year after surgery. We experienced 2 valuable cases of gastric MANEC.