A 64-year-old woman underwent allogeneic peripheral blood-derived stem cell transplantation for acute lymphocytic leukemia. She complained of dyspnea and was admitted to hospital 116 days after transplantation. Because of positive serum testing for the Aspergillus antigen and antibody, and ground-glass opacity in the right upper lobe on high-resolution computed tomography (HRCT), we made a diagnosis of pulmonary aspergillosis and administered an antifungal agent. Although tests for the Aspergillus antibody became negative and the ground-glass opacities disappeared, her dyspnea persisted. Progressive bronchiectasis was seen on HRCT, predominantly in the lower lobes. A pulmonary function test showed mixed impairment. We made a diagnosis of bronchiolitis obliterans after chronic graft versus host disease (GVHD). Prednisolone and an increased dose of tacrolimus (FK506) were administered, but type II respiratory failure progressed and she died 2 months after admission. On HRCT, each lobe was graded for bronchiectasis using a scale: 0 = normal, 1 = less than 2 x the diameter of an adjacent pulmonary artery, 2 = 2 - 3 x the diameter of an adjacent pulmonary artery, and 3 = more than 3 x the diameter of an adjacent pulmonary artery. A total score was calculated by summing the scores of all the lobes (maximum 15). In this case, the total score increased rapidly from 0 to 13 in 2 months.