Esophageal perforation is one of the most grave prognostic problems among thoracic and general surgical emergencies which necessitate urgent operative measures. In Korea,there are still many persons ingesting lye for suicidal attempt and thoracic surgeons in Korea have more chances to deal with lye burned esophagus with or without instrumental perforation than those in Western countries. Main cause of esophageal perforation in Korea is instrumental perforation in patients with lye stricture of the esophagus during diagnostic endoscopy or therapeutic bouginage. Other causes are corrosion of the esophagus due to ingestion of caustic agents, pathologic perforation, surgical trauma, stab wound and spontaneous rupture of the esophagus in our series. Therapeutic measures are various,and depend on duration of perforation, severity of its complications, pathology of perforated portion of the esophagus and degrees of inflammation at the point of perforation. The most important therapeutic measures are prevention of this grave condition during esophagoscopy, bouginage and surgical procedures on lungs and mediastinal structures and to make early diagnosis with prompt therapeutic measures. During the period of January, 1959, to December, 1971, the authors experienced 65 cases ofesophageal perforation including acquired esophagorespiratory fistula at Dept. of Chest Surgery, the National Medical Center in Seoul, and obtained following results in the series. 1. Female were 35 cases, and peak age incidence was 2nd and 3rd decades of life. 2. Among 65 cases, 43 were corrosive esophagitis or benign stricture of the esophagus due to caustic agents, 7 were patients with esophageal cancer. and there were 5 cases of esophageal perforation developed after pneumonectomy or pleuropneumonectomy. 3. Causes of perforation are instrumental perforation in 45, acute corrosion in 7, pathologic perforation in 7, surgical trauma in 3, stab wound in 2 cases, and one spontaneous rupture of the esophagus. 4. Most frequent sites of esophageal perforation were upper and mid thoracic esophagus, and 8 were cases with cervical esophageal perforation. 5. Complications of esophageal perforation were mediastinitis in 42, empyema or pneumothorax in 35, esophagorespiratory fistula in 12, retroperitoneal fistula or abscess in 5,pneumoperitoneum in 3, and localized peritonitis in 1 case. 6. Cases with malignant esophagorespiratory fistula were only 3 in the series which is predominant cause of acquired esophagorespiratory fistula in Western countries. 7. Various therapeutic measures were applied with mortality rate of 27.7% in the series. 8. In usual cases early treatment gave better prognosis, and least mortality rate in cases with perforation in mid thoracic esophagus. 9. Main causes of death were respiratory complications,acute hemorrhage with asphyxia, and septic complications. 10. Esophageal perforation developed after pneumonectomy gave more difficult therapeutic problems which were solved in only 1 among 5 cases.