Hepatoid adenocarcinoma of the stomach is a rare type of gastric carcinoma with an extremely poor prognosis. We describe a 72-year-old man who underwent esophagogastroduodenoscopy which revealed 50 mm exulcerated lesion with a central necrosis on the lesser curvature and the posterior wall of the body of the stomach. Gastric biopsy revealed a poorly differentiated (anaplastic) adenocarcinoma. The serum level of alpha-fetoprotein (AFP) was (3220 ng/mL). After diagnosis of AFP-producing gastric adenocarcinoma, total gastrectomy, with splenectomy, was performed. The tumor showed immunohistochemical positivity for AFP and Hep Par 1. According to these histopathological and immunohistochemical findings, the tumor was diagnosed as hepatoid adenocarcinoma. At 24 months postoperatively the patient is still alive without metastatic disease on repeated abdominal CTs. Because of the poor prognosis for this histological type of tumor, accurate diagnosis of hepatoid adenocarcinoma is important, and long-term follow-up is required.