Choriocarcinoma is a malignant tumor arising from chorionic villi following normal or abnormal gestation. It rarely originates in the extragonadal region such as retroperitoneum and mediastinum. In these extragonadal choriocarcinomas, primary gastric choriocarcinoma is extremely rare. A 37-year old woman with primary choriocarcinoma of the stomach presented with amenorrhea and anemia. Serum level of β-hCG was moderately elevated. There was gastric choriocarcinoma with histologic pattern of adenocarcinoma. We wish to report the extremely rare finding of a choriocarcinoma occurring as a primary gastric neoplasm with gynecologic symptom.