Rupture of the main bronchus following closed injury to the chest is a comparatively rare accident. The late recognition of this injury is attended by difficulties in management which may endanger life or expose the patient to distressing months and years of arduous therapy. This case was a 17 year old female who was a high school student. The patient had sustained a crushing injury to her right hemithorax and had been taken to an emergency hospital where right closed thoracostomy had been performed for a tension pneumothorax. She improved following this procedure but massive atelectasis of the right lung developed on the 13th day after trauma and transferred to our hospital. Bronchoscopy disclosed granulation tissue in the right main stem bronchus and end to end anastomosis of the bronchus was performed. Postoperative course was uneventful.