In asthma and chronic obstructive pulmonary disease (COPD), an important step in simplifying management and improving adherence with prescribed therapy is to reduce the dose frequency to the minimum necessary to maintain disease control. Fixed-dose combination (FDC) therapy might enhance compliance by decreasing the number of medications and/or the number of daily doses. Furthermore, they have the potential for enhancing, sensitizing, and prolonging the effects of monocomponents. Combination therapy with an inhaled corticosteroid (ICS) and a long-acting β-agonist (LABA) is considered an important approach for treating patients with asthma and patients with severe COPD who have frequent exacerbations. Several ICS/LABA FDCs are now commercially available or will become available within the next few years for the treatment of COPD and/or asthma. Several studies demonstrate that there are a number of added benefits in using combinations of β2-agonists and antimuscarinic agents. In particular, LABA/long-acting antimuscarinic agent (LAMA) combination seems to play an important role in optimizing bronchodilation. Several once-daily and twice-daily LABA/LAMA FDCs have been developed or are in clinical development. LAMA/ICS FDCs seem to be useful in COPD and mainly in asthma, in patients with severe asthma and persistent airflow limitation. The rationale behind the ICS/LABA/LAMA FDCs seems logical because all three agents work via different mechanisms on different targets, potentially allowing for lower doses of the individual agents to be used, accompanied by improved side effect profiles. In effect, in clinical practice, concomitant use of all three compounds is common, especially in more severe COPD but also in the treatment of adults with poorly controlled asthma despite maintenance treatment with high-dose ICS and a LABA.