OBJECTIVES: Incidence of chronic obstructive pulmonary disease (COPD) has increased globally. The respiratory medications were the main treatment strategies to control for COPD disease progression. The purpose of the current study was to explore the utilization pattern of respiratory medications among COPD patients in Taiwan. METHODS: A retrospective observational study was conducted by using 2000 and 2005 Longitudinal Health Insurance Databases (two million random samples). A cohort of national health insurance beneficiaries with any newly diagnosis for COPD (International Classification of Diseases, Ninth Revision[ICD-9] codes=491.x, 492.x, 496) in 2006 and aged greater than 40-year-old was identified. These COPD patients were assessed and followed for one-year from the date of their first prescription of any inhaled COPD medications (index date) and their persistence of each class of COPD medications was evaluated. RESULTS: A cohort of 7838 new COPD cases was identified in 2006. They were about 68.9±12.6 years old and male was predominant (67%). Of all, 95% were coded with 496. However, only 579(6.9%) were ever prescribed with inhaled COPD medications in 2006. The days to the first prescription of inhaled COPD medications after diagnosis were 26 days in average, and up to 336 days. Only 5.5% to 19% of patients continued on the index drug for more than 6 months, which decreased to 1 to 5% at 12 months. The long-acting muscarinic antagonist (LAMA) showed the highest persistence among the other medications, whereas inhaled corticosteroid (ICS) had the lowest. CONCLUSIONS: Respiratory medications were obviously under-utilized in Taiwanese patients with COPD. Further study is needed to explore the consequence of such phenomenon and its potential resolutions.