The gastric remnant cancer is defined as a cancer that has developed 5 or more years after distal gastric resection for benign diseases of the stomach. The choriocarcinomatous differentiation of adenocarcinoma in the stomach is a very rare tumor. A 75-year-old woman underwent resection of remnant stomach which she had operated for benign gastric pathology 54 years ago. Pathologic examination of the resection revealed areas of choriocarcinomatous differentiation in addition to classical adenocarcinoma. In the literature on English language, this report presents the first case of adenocarcinoma associated with choriocarcinomatous differentiation in the gastric remnant. The treatment of these patients depends on the clinical setting, and early diagnosis is an important factor for the treatment strategies. Therefore, due to the probability of arising adenocarcinoma in the remnant stomach, the patient should be investigated with endoscopic examination periodically, despite the long postoperative period.