We report an 8-year-old boy who developed cough and respiratory failure 7 months after bone marrow transplantation (BMT) coinciding with the onset of chronic graft-versus-host disease (GVHD). Lung function data, imaging studies, lung biopsy and bronchoalveolar lavage were consistent with the diagnosis of bronchiolitis obliterans organizing pneumonia. While this has been reported in association with chronic graft-versus-host disease in one adult case previously, we report the simultaneous occurrence of BOOP and chronic GVHD in a child after bone marrow transplantation for the first time.