We report a case of massive endobronchial hemorrhage following a fistula formation of the right pulmonary artery to the right mainstem bronchus in a 15-year-old girl. The fistula had occurred 39 days after the patient had undergone bilateral lung transplantation for cystic fibrosis. The post-transplantation course was remarkable for bronchial colonization by Aspergillus at the site of right bronchial anastomosis and an episode of spontaneous, self-limited hemoptysis on postoperative day 17. A massive endobronchial hemorrhage during surveillance bronchoscopy occurred 39 days after transplantation. Immediate intervention, including rigid bronchoscopy followed by surgery, was effective in saving the patient. The pathophysiologic hypothesis to explain the fistula of the right pulmonary artery to the right mainstem bronchus probably involves ischemia of the anastomosis with necrosis of the suture zone complicated by endobronchial infection with Aspergillus. Rigid bronchoscopic intervention associated with an excellent medical surgical collaboration was pivotal in successfully rescuing the patient.