OBJECTIVE: Diffuse panbronchiolitis (DPB) is a chronic progressive disease of the lower respiratory tract, which is prevalent in Asian population. So far, many DPB cases have been found in adults in China. To our knowledge, no pediatric DPB case has ever been reported in China. We describe the first pediatric DPB case in Chinese literature and the second case in the English-language literature. METHOD: The clinical manifestations, characteristic imaging and histological features of this DPB case were summarized. RESULTS: The patient was a 13-year old girl complained of chronic productive cough with wheezing. Chest auscultation revealed fine moist rales and wheezing over both lung fields. The chest X-ray showed small nodules and reticular opacities in left lower lobe. High-resolution thorax computerized tomography (HRCT) demonstrated bilateral diffuse small centrilobuler nodules and bronchial wall thickening or bronchiectasis in some parts of the lungs. Histopathological examination of transbronchial biopsy specimen revealed lymphocytes and foamy histocytes infiltrated in the walls of bronchi, respiratory bronchioles and adjacent alveoli. Lymphoid follicles were present around some bronchi. Sinus radiographs revealed sinusitis. Lung function studies showed obstruction and restriction. PaO2 was 65 mm Hg. The diagnosis of DPB was made according to the current diagnostic criteria. Low-dose erythromycin [5 - 10 mg/(kg.d)] was effective. CONCLUSION: DPB could occur in children in China. The major diagnostic clues may include the following: (1) persistent cough, sputum, and dyspnea; (2) coexistent chronic sinusitis; (3) bilateral diffuse small nodular opacities on HRCT. Low-dose erythromycin was effective in treatment of the case with DPB.