Platypnea-orthodeoxia syndrome is a rare entity most often related to an interatrial right-to-left shunt. We report the case of a patient who developed platypnoea-orthodeoxia shortly after a blunt chest wall trauma. Definite diagnosis was obtained with transoesophageal echocardiography using contrast in upright and recumbent position. A Medline search did not reveal any other case report of the syndrome after chest wall injury.