Two cases of intraabdominal organ injuries due to blunt chest trauma are reported. A 58-year-old man was admitted to our hospital with multiple rib fractures, hemopneumothorax and left flail chest. An emergency operation was performed and intraoperative findings revealed that the fractured rib was penetrating through the diaphragm to the stomach. A 52-year-old woman was admitted to our hospital with left multiple rib fractures and hemopneumothorax. Her treatment included chest tube drainage, but a week after admission, intraabdominal bleeding occurred due to a ruptured spleen, necessitating an emergency operation (splenectomy). Blunt chest trauma injury is usually accompanied by multisystem injury. Therefore, it is important to detect intraabdominal injury during an emergency operation and the follow-up period.