ObjectiveTo improve clinicians' awareness of cryptogenic organizing pneumonia (COP).MethodsThirty-three inpatients with COP, who had been diagnosed by pathology in Nanjing Drum Tower Hospital during January 2013 to December 2016 were collected. Their clinical manifestations, laboratory tests and imaging data were reviewed and analyzed retrospectively.ResultsThirty-three cases consisted of 18 males and 15 females, and the mean age was (58.7±13.5) years old. Most patients had subacute or insidious onset. The common symptoms were cough, fever, shortness of breath and chest tightness. About half of patients revealed inspiratory crackles or velcroes. Autoantibodies and anti-neutrophil cytoplasmic antibodies were negative. High-resolution computerized tomography findings of COP included bilateral patchy areas of air-space consolidation that showed predominantly subpleural or peri-bronchovascular distribution, focal nodules, enlarged hilar or mediastinal lymph nodes and pleural effusion. 25 patients were treated with glucocorticoid, 6 with macrolid, and 2 were only followed up without drug treatment.ConclusionsClinical manifestations, laboratory tests and imaging features are important clues to diagnose COP. Diagnosis depends on pathology. Meanwhile, definite pathogen and potential underlying diseases must be excluded.