A 48-year-old man came to the emergency department with altered consciousness and hemoperitoneum following a pedestrian traffic accident. He underwent immediate emergency laparotomy, and on the second day, he required craniectomy because of increase of intracranial hemorrhage. A chest radiograph taken 7 days after admission, showed elevation of the right hemi-diaphragm, and follow-up chest CT showed a right-sided rupture of the diaphragm, which was surgically repaired. Rupture of the diaphragm can be easily overlooked and the diagnosis delayed, especially in unstable patients with multiple trauma or altered level of consciousness, as in the case reported here. [ J Trauma Inj 2017; 30: 16-20 ]