Long-acting bronchodilators and inhaled corticosteroids (ICS) are the cornerstones in treatment of chronic obstructive and inflammatory pulmonary diseases. However, non-adherence to guidelines is widespread. Detailed information on real-life treatment patterns is needed to promote rational use. We aimed to investigate nationwide time trends in individual-level treatment patterns of long-acting bronchodilators and ICS. Using nationwide Danish health registries, we identified all Danish adults with a prescription for long-acting bronchodilators and/or ICS from 2000 to 2016. We investigated the total use of long-acting bronchodilators and ICS, the proportion of current users and the rate of new users over time. Finally, we assessed treatment persistence. We included 23,061,681 prescriptions for long-acting bronchodilators and ICS issued to 805,860 individuals from 2000 to 2016. Over this period, the total annual amount of prescribed long-acting bronchodilators and ICS increased by 39%. Similarly, the proportion of adult users increased from 2.6% to 4.5%, mainly driven by the introduction of combination therapy and long-acting muscarinic antagonist (LAMA). Although the rate of new users of fixed-dose combination drugs increased substantially over time, the overall rate of new users was stable. In general, the proportion of patients on therapy after 1 year was low (25–53%), especially among young individuals and users of ICS. We document a pronounced increase in the total use of long-acting bronchodilators and ICS over time, mainly driven by the introduction of combination drugs and LAMA. Special attention should be paid to the low level of persistence, especially among young individuals and users of ICS.