pneumonia in cystic fibrosis has hitherto been considered a nonspecific reparative process. We report on an adult patient with cystic fibrosis and histologically proven bronchiolitis obliterans organizing pneumonia, who experienced sustained clinical improvement under corticosteroid therapy. This case suggests that bronchiolitis obliterans organizing pneumonia may be a distinct pulmonary complication in cystic fibrosis and improve with specific therapy. Copyright (C) 2000 S. Karger AG, Basel.