Résumé : Immediately after heart-lung transplantation for cystic fibrosis, a patient had development of a right lower lobe retrocardiac density that persisted on all postoperative chest radiographs. A computed tomographic examination of the thorax performed 3 weeks after surgery showed that there was partial collapse of the left lower lobe in the right hemithorax. The patient required a posterolateral thoracotomy for cure.