Objective To investigate the association between chronic obstructive pulmonary disease (COPD) and lung cancer. Methods A case-control study was undertaken, with 180 cases of lung cancer and 200 cases of controls. Results The odd of lung cancer was higher in patients with COPD, emphysema, chronic bronchitis, and pulmonary tuberculosis （P<0.05). The odd of lung cancer increased significantly in patients with a family history of lung cancer or COPD （P<0.05). The odd of lung cancer also increased when forced expiratory volume in one second （FEV1）<80%. Conclusion Patients with COPD or a family history of COPD have higher risk of lung cancer.
