A 16-month-old infant ingested an alkaline battery, 22 mm x 5 mm, which became entrapped in her esophagus. She was brought to the emergency department with a four-day history of vomiting. After tube thoracostomy, the battery was removed by esophagoscopy. However, she experienced cardiac arrest in the intensive care unit. Post mortem examination revealed exsanguination by perforation of the posterior aspect of the aortic arch as the cause of death. Microscopic examination showed liquefaction necrosis through the mucosa and submucosa of the esophagus into the upper mediastinum and right pleural space. The possible role of the alkaline center of the battery causing perforation is presented.