Objective To investigate the clinical manifestations, lung function and therapy of patients with primary bronchogenic carcinoma complicated with chronic obstructive pulmonary disease ( COPD) . Methods 365 patients with primary bronchogenic carcinoma were recruited retrospectively. The patients were analyzed by COPD-complicated and COPD-free groups. The clinical manifestations, lung function ( especially FEV1 ) , pathological types and progression-free survival ( PFS) were analyzed. The use of inhaled corticosteroids for treatment of COPD was also recorded. Results There was 62.2% patients( 227 cases) complicated with COPD with an average age of ( 66.1 ±9.3) yrs, 77. 5% of male, 82. 4% of smokers, and 46. 3% of past histories of respiratory disorders. Those in COPD-free were aged ( 54.8 ±5.6) yrs, with 55.8% of male, 62.3% of smokers, and 30.4% of past histories of respiratory diseases. The COPD-complicated patients had lower lung function than that of COPD-free [ ( 68.6 ±9.7) % vs. ( 75.3 ±7.5) % in FEV1%pred and ( 65.9 ±8.5 ) % vs. ( 75.6 ±9.1 ) % in FEV1 /FVC, P lt; 0.05 ] . The COPDcomplicated patients were more likely to have squamous carcinoma ( 43.2% vs. 31.2% , P lt; 0.05) and small cell lung cancer ( 20.7% vs. 15.2% , P lt; 0.05) . Moreover, performance status ( PS) scores ( 3.3 ± 0.5 vs. 2.8 ±0.4) and PFS ( 5.9 ±1.6 vs. 7.5 ±2.1) were worse in the COPD-complicated patients than that of the COPD-free patients. Only 71 cases of the COPD-complicated patients received regularly inhaled corticosteroids for COPD treatment. These patients had better PS scores and PFS than others without corticosteroids treatment. Conclusions Primary bronchogenic carcinoma patients with COPD comorbidity are commonly encountered. Clinicians should be aware of the clinical manifestation and corticosteroids prescription should be recorded to improve the quality of life and prognosis.