Introduction: Chronic Obstructive Pulmonary Disease (COPD) exacerbations contribute to the overall severity in individual patients because they are associated with airway inflammation, pulmonary function loss, decreased quality of life and increased mortality. Although, identifying frequent exacerbator patients is important due to severe outcomes associated with frequent exacerbator phenotype in COPD patients there is no single biomarker which can differentiate this phenotype. Iron responding protein-2 (IRP2) is the protein product of IREB2 gene, which is a COPD susceptibility gene that regulates cellular iron homeostasis and has a key role in hypoxic conditions. Previous research indicates that IREB2 expression in lung tissue is associated with spirometric measurements and emphysema in COPD. In this study, our aim was to investigate whether serum IRP2 levels were associated with frequent exacerbator phenotype, to evaluate whether IRP2 levels in serum are associated with pulmonary functions and selected systemic inflammation biomarkers.