Objective To describe the characteristics of pulmonary involvement in Crohn was described and relevant literature were reviewed. Results The patient showed chief complaints of cough,expectoration and fever. The chest CT scan revealed bilateral lung opacity shadows ,Ziehl-Neelsen acid-fast stain examination in sputum and cultures got negative results for many times. Chest CT scan revealed no dissipation after different antimicrobials treatment for 2 months. The fiberoptic bronchoscopy was performed, which showed nodular lesions in the trachea and beside the opening of right upper lobe. Histopathology showed polypoid hyperplasia of granulation tissue. The bilateral patchy opacity dissipated, the nodes in the trachea disappeared and the nodes beside the opening of right upper lobe diminished obviously after the patient was treated with oral prednisone and salicylazosulfapyridine (SASP). Pulmonary involvement in Crohn disease is very rare and it can involve any part of the lungs. The most common manifestations are cough, expectoration and fever. The lung and gastrointestinal system often share similar pathogenetic changes: granulomatous inflammation. These patients responded well to combination use of glucocorticoid and SASP. Conclusion Pulmonary involvement should be considered when patients with Crohn disease manifested with respiratory symptoms, which can be definitely diagnosed by clinical features and histopathological examintation.