Neuroendocrine carcinoma of the stomach is an uncommon tumor, usually associated with highly malignant biological behavior and extremely poor prognosis. In this report, we described a case of advanced neuroendocrine carcinoma of the stomach with the peripancreatic lymph node metastases which was treated with pancreaticoduodenectomy with extended lymphadenectomy. The patient was admitted to our hospital for anemia. An upper gastrointestinal endoscopy revealed a 4x4-cm fungating tumor with its fundus locating mainly in the duodenal bulbus and extending to the gastric antrum, and tumor biopsy revealed the histological findings of adenocarcinoma. Computed tomography (CT) showed a large mass in the duodenal bulbus with regional lymph node metastases. The patient's disease was diagnosed as primary duodenal cancer with regional lymph node metastases preoperatively. During the operation, an obviously swollen lymph node on the anterior surface of the head of the pancreas 4.0 x 3.5 cm in size was found growing into the parenchyma of the pancreas head and could not be separated from the pancreas, and the swollen lymph node along the superior mesenteric vein was also hard and suspected to be a metastatic node. A pancreaticoduodenectomy with extended lymphadenectomy was performed to achieve a radical resection. Histopathologically, the origin of the primary tumor was considered as a gastric origin, and the tumor was composed of diffused small cells with a moderate mitotic index and occasional rosette formation. Immunohistochemical investigations of the neoplastic cells confirmed the tumor to be neuroendocrine carcinoma. The obvious swollen lymph node on the anterior surface of the head of the pancreas and the swollen lymph node along the superior mesenteric vein were also identified as metastatic lymph nodes. Adjuvant chemotherapy with TS-1 was administered on an out-patient basis 6 weeks after the operation. The patient is well and has now been free of symptoms of recurrence and metastasis for 8 months.