The caustic drugs are classified into acid and alkali. Oral intake of these drugs cause histological injuries to the surfaces of oral cavity, laryngopharynx, and esophagus. Caustic drugs such as detergents and brilliants are easily contacted at homes. However, until now, the epidemiology and the clinical statistics of caustic drug ingestion in Korea were not carried out. This is a case report of sodium hydroxide - lye, a caustic drug more toxic than the others - ingestion with complication of gastroesophageal perforation, rapidly progressed mediastinitis and prompt death in the course of treatment.