Hematoma of gastric wall is very rare, and occasionally associated with coagulopathy, trauma, peptic ulcer disease, and therapeutic endoscopy. Ischemic gastric necrosis is also rare because of the abundant anastomotic supply to the stomach, and it is usually associated with surgery and disruption of the major vessels. Endoscopic submucosal injection of hypertonic saline-epinephrine (HS-E) is a safe, cost-effective, and widely used therapy for hemostasis but it may cause tissue necrosis and perforation. We describe a case of gastric wall hematoma with oozing bleeding after endoscopic gastric mucosa biopsy in 71-year old woman with chronic renal failure and angina pectoris undergoing anti-platelet medication. We injected a small dose of HS-E (7ml) for controlling oozing bleeding. Two days later, endoscopy showed huge ulcer with necrotic tissue at the site of previously hematoma. Therefore we should pay particular attention for hematoma and mucosal necrosis when performing endoscopic procedure in a patients with high bleeding and atherosclerotic risk.