Chest injuries due to blunt trauma often result in severe derangements that lead to death. And we have to diagnose and treat the patients who have blunt chest trauma immediately and appropriately. A clinical analysis was made on 324 cases of chest injury due to blunt trauma experienced at department of Thoracic and Cardiovascular Surgery, College of Medicine, Kyung Hee University during 8-year period from 1972 to 1979. Of 324 patients of blunt chest injuries, there were 189 cases of rib fracture, 121 of hemothorax or/and pneumothorax, 108 of soft tissue injury of the chest wall only, 41 of lung contusion, 24 of flail chest, 13 of scapular fracture, 7 of diaphragmatic rupture and others. The majority of blunt chest injury patients were traffic accident victims and falls accounted for the next largest group of accidents. Chest injuries were frequently encountered in the age group between 3rd decade and 4th decade [60%] and 238 patients were male comparing to 86 of female [Male: Female = 3:1 ]. In the patients who have the more number of fractured ribs, the more incidence of intrathoracic injury and intraabdominal organ damage were found. The principal associated injuries were head injury on 58 cases, long bone fractures on 37, skull fractures on 12, pelvic fractures on 10, renal injuries on 6 and intraabdominal organ injuries on 5 patients. The principle of early treatment of chest injury due to blunt trauma were rapid reexpansion of the lung by closed thoracotomy which was indicated on 96 cases, but open thoractomy was necessary on 14 cases because massive bleeding, intrapleural hematoma and/or fibrothorax, or diaphragmatic laceration-On 15 cases who were young and have multiple rib fracture with severe dislocation delayed elective open reduction of the fractured ribs with wire was done on the purpose of preserving normal active life. The over all mortality was 2.8% [9 of 324 cases] due to head injury on 3 cases, massive bleeding on 2,wet lung syndrome, acute renal failure on 1 and septicemia on 1 patient.[KTCS 1979;4:418-423]