Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct procedure designed to sustain the circulation until definitive hemostasis is obtained. The device is indicated in trauma patients with abdominal trauma and/or pelvic fractures, but there is limited evidence for its use in gastrointestinal bleeding. A 76-year-old woman was admitted to the emergency department of our hospital because of shock, manifesting as hematemesis. We performed emergency endoscopy and detected active bleeding from a gastric ulcer. Achieving hemostasis was difficult, and she experienced shock again during the procedure, leading to cardiopulmonary arrest. REBOA was performed after the return of spontaneous circulation because she continued to be in a state of shock. Her blood pressure rose, and endoscopic hemostasis was continued with balloon inflation, but it didn’t stop the bleeding completely, so we shifted to emergency laparotomy and performed suture hemostasis. The patient developed no postoperative complications and was transferred to another hospital. REBOA can be effective at improving the hemodynamic status in patients with uncontrollable gastrointestinal bleeding.