Background: Patients with chronic obstructive pulmonary disease (COPD) remain undiagnosed and potentially unknown until the more advanced stages of the disease. The rate of FEV1 decline was greater in patients with less severe disease than those with more severe disease. We aim to investigate the cost-effectiveness of inhaled treatment in early COPD. Methods: We reviewed the database of Korean adults recording less than 0.7 of FEV1/FVC from the Korean National Health and Nutritional Examination Survey (KNHANES) and Korean National Health Insurance (NHI) from 2007 to 2009. The early COPD was determined with more than 50% of FEV1. Results: 0f 1,919 patients who identified with early COPD in KNANES, 120 patients were confirmed that they visited hospital within the next year after diagnosis in NHI database. 58 (48%) patients were on inhaler for COPD. The others took oral medications. In patients using inhaler regularly, medical costs of outpatient clinic were significantly higher(P=0.012). However, totally medical costs including admission and emergency room were not different whether using inhaler or not. Multiple linear regression adjusting with age, sex, using inhaler, FEV1, income showed that smoking status was significant factors affecting the number of medical utilizations(β=4.26, P=0.008) and cost(β=658352, P=0.022). Conclusions: In early COPD patient, using inhaler did not cost more than taking the other type. The uncontrolled aggravating factors such as smoking increased directly medical costs in early COPD.