The aim of this cross-sectional case-control study was to determine the relationship between serum cystatin C (sCysC) levels and lung function in elderly male patients with chronic obstructive pulmonary disease (COPD). This study included 251 Chinese men (age≥65years) who were divided into COPD (n=129) and non-COPD (n=122) groups. Participants underwent lung function and laboratory testing, including measurement of sCysC levels. Relationships between sCysC concentration and indices of lung function were assessed by multiple regression analysis. Participants in the COPD group displayed higher sCysC concentrations (P=0.041) and lower lung function (P<0.001) compared to participants in the non-COPD group. Multiple linear regression analyses revealed that the reciprocal of the sCysC concentration (1/sCysC) was positively associated with the predicted forced expiratory volume in 1s in all subjects (β=0.156, P=0.009). The findings indicate that high sCysC levels were directly associated with decreased lung function in elderly Chinese men with COPD. High sCysC concentration may be a potential indicator of impaired lung function, and its application may improve the diagnosis and assessment of COPD severity in elderly male patients.