Introduction: Hydrogen peroxide poisoning can cause death. The chemical reactions in the body will produce complications, such as stroke, perforation of the gut, and embolism. These complications are most likely seen with high concentrations. Case Presentation: The patient was a 55-year-old female, who tried to commit suicide by ingestion of approximately 150 cc of hydrogen peroxide. She was brought to the emergency room for medical treatment. During the physical examination, the patient had air in the neck and mediastinum, which is a strong indication of acute mediastinitis. The patient was treated with esophagectomy and feeding jejunostomy. The pathology reported first degree burns of the esophagus without perforation. The patient underwent reconstructive surgery and treatment for eight weeks, yet she died during surgery as a result of low ejection fraction (EF). Conclusions: In this case, the patient intentionally ingested a low concentration (15%) of hydrogen peroxide and as a result experienced first degree burns in the esophagus. The patient did not require surgery for treatment. The presence of white mucus and air around the esophagus and stomach was thought to be indicative of acute mediastinitis and mistakenly exposed the patient to major surgery.