Objective To investigate the clinical features and bronchoalveolar lavage (BAL)therapy of postinfectious bronchiolitis obliterans (BO) in children. Method Ten children, who had post-infectious BO from February 2009 to February 2010, received BAL therapy, and were retrospectively analyzed. The data included pathology,chnical feature,chest HRCT scan, BALF cellular, levels of blood T cell subtypes and outcome of BAL therapy. Results Adenoviruses or mycoplasma pneumoniae were the most common etiologic agents (4/10, respectively). All patients presented persistent or recurrent dyspneic respirations and wheezing since the initial lung infection. The findings of HRCT included mosaic pattern of perfusion (6/10), accompanied by gas retention,bronchiectasis, atelectasis and bronchial wall thickening. The percentage of neutrophils in BALF was significantly increased in all cases (10/10). There were predominance of CD8+ T cell subtype (9/10) and lower ratio of CD4 +/CD8+ ( 10/10)in blood. Reduced symptoms and shortened hospital stay of BO in 9 of all 10 cases were observed after BAL therapy. Conclusions Severe adenovirus or mycoplasma pneunoniae bronchiolitis and/or pneumonia has higher risk for developing BO in children. Increased percentage of neutrophils in BALF and predominance of CD8 +T cell subtype may play an important role in the mechanism of BO. BAL therepy can reduce the respiratory symptoms of BO in children.