Carcinosarcoma of the stomach is regarded as a rare malignant neoplasm composed of both carcinomatous and sarcomatous components in a given tumor. Few cases have been reported since 1904. This is a case of carcinosarcoma of the stomach in a 61-year-old man. He suffered from indigestion, vomiting, and epigastric pain. Endoscopic finding showed a huge protruding mass with intact mucosa on the posterior wall of the antrum up to the pylorus. Surgery was performed and carcinosarcoma with pancreatic invasion was confirmed by pathology. (Korean J Gastrointest Endosc 19: 107 ∼110, 1999)