A solid scientific rationale and an increasing body of clinical evidence fully support the use of an antimuscarinic agent combined with a β-agonist in chronic obstructive pulmonary disease. In this article, we focus on the development of an inhaled fixed dose combination (FDC) of two 24-h bronchodilators, umeclidinium bromide and vilanterol (UMEC/VI) (ANORO). Several pivotal clinical trials have documented the impact of this combination on lung function and other outcome measures such as quality of life, dyspnea, rescue medication use and exercise capacity, with no clinically meaningful treatment-related changes in vital signs or clinical laboratory parameters. These results allow us to predict that UMEC/VI will have a role in the maintenance treatment of chronic obstructive pulmonary disease. It remains to determine its impact on exacerbations. In any case, trials comparing UMEC/VI with other dual bronchodilator FDCs, and also with inhaled corticosteroid/long-acting β-agonist FDCs, are needed to assess the advantages, if any, of UMEC/VI FDC over other therapies.