PURPOSE: Diffuse panbronchiolitis(DPB) is a chronic inflammatory airway disease of unknown causes mainly affecting the respiratory bronchioles and the more proximal bronchi. Findings on chest radiographs and high-resolution CT(HRCT) are well known and Akira classified HRCT findings of DPB into four types. Purpose of this study is to evaluate the relationship between findings of HRCT and PFT. METHODS AND MATERIALS: We retrospectively analyzed the chest radiographs and HRCT images of eleven patients with DPB and compared CT classification with pulmonary function test. RESULTS: Chest radiographs usually showed small nodular opacities throughout the both middle and lower lungs. The HRCT findings of DPB were centrilobularly distributed small nodular densities, branching linear densities contiguous with small round densities, dilated and thickened peripheral and central airways including bronchioles. More than one CT type by Akira's classification, usually two or three types, were found in nine patients. There was good correlation between CT types and FEV1%(p<0.05), CT types and FEV1/FVC (p<0.05) respectively. CONCLUSION: HRCT seems to be more useful for diagnosis and disease progression of DPB as compared with the chest radiographs or clinical stage such as pulmonary function test.