Aortoesophageal fistula (AEF) is an extremely rare but lethal cause of massive gastrointestinal hemorrhage. Characteristic symptoms are mid-thoracic pain, sentinel minor hemorrhage, and massive hemorrhage after a symptom-free interval. Prompt diagnosis and immediate treatments are necessary to reduce mortality. However, AEF is difficult to diagnose because it is uncommon and often leads to death with massive bleeding before proper evaluation. We report a case of endoscopic diagnosis of AEF that did not present with hematemesis; it was treated with thoracic endovascular aortic repair (TEVAR) and surgery. A 71-year-old female presented to the emergency department with epigastric discomfort. Endoscopy demonstrated a submucosal tumor-like protrusion and pulsating mass with blood clots. Contrast-enhanced chest CT confirmed AEF due to descending thoracic aortic aneurysm. The patient immediately underwent TEVAR to prevent massive bleeding and subsequently underwent surgery. Endoscopists should consider AEF if they see a submucosal tumor-like mass with a central ulcerative lesion or a pulsating protrusion covered with blood clots in mid-esophagus during an endoscopy.