Double primary cancer of the stomach and esophagus has been revealed a very low incidence in the world except Japan and reported only 6 cases in Korea. Furthermore, it is difficult to manage this type of double cancer because esophageal cancer has a biologic tendency to early metastasis. This paper is concerned with a case of double primary cancer, which we have synchroniously confi~rmed esophageal squamous cell carcinoma and gastric adenocarcinoma with gastrofiberscopic biopsy, and then treated them by radical resec tion and systemic chemotherapy. (Kor J Gastrointest Endosc 15: 721-727, 1995)