Background/aim: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. In COPD patients, various inflammatory markers such as cytokines and acute phase proteins, which show systemic inflammation in the circulation, increase during exacerbations. In our study, we aimed to determine the relationship between serum SP-D levels and exacerbation severity, clinical course of the disease, and early mortality after discharge.Materials and methods: Fifty hospitalized patients with COPD acute exacerbation (46 male and 4 female) were recruited in this study. Thirty-three of the subjects (31 male and 2 female) were reevaluated after discharge. Venous blood samples were taken from all patients and followed up for exacerbation frequency, hospital admission, and mortality for 12 months.Results: Serum SP-D levels in the stable period of the patients were lower than exacerbation (P