In this study, we aimed to investigate the role of presepsin in detecting concomitant pneumonia in patients presenting with acute exacerbation of chronic obstructive pulmonary disease (COPD) in the emergency department. Three groups were formed in the study. Group 1: patients diagnosed with acute exacerbation of COPD; group 2: patients with acute exacerbation of COPD + pneumonia; group 3: healthy individuals. Presepsin levels of the patients in group 2 were significantly higher than those of group 1 and group 3 (p < 0.05). There was a statistically significant difference in erythrocyte sedimentation rate, CRP, procalcitonin and presepsin values between two patient groups (p < 0.05). Presepsin can be used to diagnose pneumonia in patients with acute exacerbation of COPD admitted to the emergency department.