Objective To investigate the cognitive impairment and the plasma levels of neutrophil gelatinase associated lipocalin (NGAL) and endothelin-1 (ET-1) in the patients with chronic obstructive pulmonary disease (COPD) . Methods In this study, 312 cases in COPD group and 89 healthy people in control group were enrolled. The subjects in both groups received the MoCA (Montreal Cognitive Assessment Scale) assessment and detection of plasma levels of NGAL and ET-1. Results Compared with the control group, the scores of visual spatial executive ability, attention and delayed recall and the total scores of MoCA were lower in the COPD group (P < 0.05). The plasma levels of NGAL and ET-1 in the COPD group were higher than those in the control group (P < 0.05). In the control group, the plasma levels of NGAL and ET-1 in the people with cognitive impairment were higher than those in the people without cognitive impairment (P < 0.05). In the COPD group, the plasma levels of NGAL and ET-1 in the patients with cognitive dysfunction were higher than those in the patients without cognitive impairment (P < 0.05). Conclusions Compared with normal controls, cognitive impairment in the COPD patients is more severe, and the plasma levels of NGAL and ET-1 are significantly higher in the patients with cognitive impairment.