Objective: To investigate the clinical features and diagnostic procedures for diffuse panbronchiolitis in Chinese patients., Methods: With literature review, the clinical features and diagnostic procedures of diffusely panbronchiolitis in a series of 9 patients with histopathological confirmation were retrospectively described and discussed., Results: Of the 9 cases, 8 had persistent cough, sputum production and exertion dyspnea, 7 had chronic sinusitis, 9 had centrilobular micronodules on chest CT, 7 had coarse crackles, 4 had FEV(1)/FVC < 70%, 5 had PaO(2) < 80 mm Hg and 1 had titer of cold hemagglutinin > or = 1:64. According to the Japanese revised clinical diagnostic criteria for diffuse panbronchiolitis, definite diagnosis could be made in 4 cases, probable in 3 and excluded in 2 cases, respectively, but it was clinically diagnosed or suspected only in 2 cases before clinicopathological confirmation, the remaining 7 cases were missed or mistaken for other diseases. Of the 9 cases, 8 had received transbronchial biopsy and all showed non-specific inflammation, which was in agreement with but nondiagnostic for diffuse panbronchiolitis., Conclusions: Most cases of diffuse panbronchiolitis can be clinically diagnosed or suggested according to the clinical diagnostic criteria, proposed solely by Japanese experts which should be further validated in non-Japanese populations. If difficulty in diagnosis arises, the diagnosis of diffuse panbronchiolitis should be based on its clinicopathological features and exclusion of other mimicking diseases. Of note, few cases can be confirmed by transbronchial biopsy, and in this case, surgical lung biopsy should be considered.