A 52-year-old male with severe gastrointestinal graft-versus-host disease (GVHD), developed dyspnea and irreversible airflow obstruction, 11 weeks post-allogeneic bone marrow stem cell transplantation. Based on the clinical picture and presence of 'mosaic attenuation' pattern on chest high-resolution computerized tomography (HRCT), he was presumed to have bone marrow transplantation-related bronchiolitis obliterans. Post-mortem examination revealed invasive airway aspergillosis with no evidence of bronchiolitis obliterans.