In conclusion, the COPD exacerbation rate was higher among the patients who had a history of pneumonia or a high rate of COPD exacerbation in the preceding period of 1 year. This is the first large-scale study to reveal the risk factors of COPD exacerbation in South Korea. Further clinical trials will be conducted to measure the relationship between other variables and the reduction in exacerbations for meaningful sub-populations of COPD patients.