OBJECTIVES: Chronic obstructive pulmonary disease(COPD) is a highly prevalent disease and the sixth cause of death in Korea. This study examined the national epidemiology and economic impact of COPD in Korea. METHODS: This study used the societal cost of illness framework, consisting of epidemiology of COPD, direct medical costs, direct non-medical costs, and indirect costs. National-level health survey results and insurance claim databases were used to analyze annual healthcare utilization, hospitalization costs and outpatient costs of the total Korean population (48 million people). Using a data mining technique, we identified medical claims with international classification of disease 10 codes for COPD and estimated the costs by a macro-costing method. RESULTS: The prevalence rate of COPD based on the Global Initiative for chronic obstructive lung disease(GOLD) criteria was estimated at 13.1% and its mortality rate was 14.9 persons per 1,000 population in 2008. According to the classification of the GOLD, for the population over 45 years, the stage 1 group accounted for the largest proportion(55.2%), followed by the stage 2(37.2%), stage 3(6.4%), and stage 4(1.2%). The total societal cost of COPD in 2009 was estimated at $266.4 million for 700,812 patients. The direct medical cost for COPD was $148.7 million, which includes hospitalization cost of $72.8 million and outpatient cost of $75.9 million. The direct non-medical cost, involving transportation cost and caregiver cost, was estimated at $20.4 million. Indirect costs associated with morbidity and mortality of COPD were $97.3 million. CONCLUSIONS: The study showed that the COPD had a great effect on health care costs, particularly the direct medical cost. Therefore, appropriate intervention that result in patients with COPD spending less time in the hospital are likely to be cost effective and long-term regular management is also necessary to lower the economic burden of COPD in Korea.