PURPOSE: Hepatoid adenocarcinomas of the stomach are gastric carcinomas with both adenocarcinomatous and hepatocellular differentiations. Their incidence is rare, and they usually produce large amounts of alpha-fetoprotein (AFP). They have a specific pathologic feature, frequently occur together with liver metastasis and have a poor prognosis. This study was undertaken to understand the characteristics of clinical feature. METHODS: Fourteen hepatoid adenocarcinoma cases of gastric cancer were analyzed among 3243 patients who were treated for gastric cancer at our center between Jan 1996 and August 2003 (0.43%). RESULTS: There were 13 males and one female patient, with a median age of 59 years, ranging from 40 to 75. Ten tumors were located in the antrum, 2 in the body and 2 in the fundus. The size of the tumors varied from 2.3 to 11.0 cm. Direct invasions to adjacent organ were (4 to the pancreas and 1 to the colon). Four cases had visible lymph node enlargement at the time of the operation, ranging (from 3.5 to 6.0 cm). During the operation, 2 patients were found to have metastasis to the liver, 1 to the retroperitoneum, and 1 was positive on peritoneal washing cytology. The preoperative serum CEA levels were elevated in 7 patients, and 5 in 8 patients showed very high preoperative serum AFP levels ranging from 34.5 to 3724 ng/ml. All patients underwent a gastrectomy, and a hepatectomy in cases of liver metastasis. Pathological staging revealed one in stage Ib, four in stage II, one in stage IIIb and eight in stage IV. Immunohistochemical stainings was performed on all patients. Ten cases were positive for AFP. During follow up, eight patients died due to tumor (mean survival time: 10.6 months). Five had liver metastasis and 3 a recurrence in the peritoneum. The 6 remaining patients are still alive. CONCLUSION: 1. Hepatoid adenocarcinomas are rare and preoperatively diagnosis. The preoperative diagnostic methods of pathological consideration and preoperative serum AFP levels of all gastric cancer patients are recommended. 2. Hepatoid adenocarcinomas of the stomach have frequent and early postoperative liver metastasis and a poor prognosis, not only in advanced gastric caner but also in early cancer. Therefore, a possibly curative resection and more aggressive study for liver metastasis are recommended as being mandatory, and more sufficient treatment for these cases should be investigated.