Bronchodilators are the cornerstone of pharmacological management of COPD. For patients whose conditions are not sufficiently controlled by monotherapy, combining bronchodilators of different classes, in particular an inhaled muscarinic antagonist with an inhaled β₂-agonist, seems a convenient way of delivering treatment and obtaining superior results. When administered as combination therapy, short-acting bronchodilators provide superior bronchodilation compared with individual agents given alone. More recently, long-acting β₂-agonists (LABAs) and muscarinic antagonists (LAMAs) have been introduced, and current guidelines recommend regular use of these agents alone or as concurrent therapy in COPD to maximize bronchodilation. In particular, the combination of a LABA plus LAMA seems to play an important role. This article illustrates the scientific rationale for combining LABAs and LAMAs in COPD, reviews the clinical evidence to support these agents given in combination, and discusses their potential role in the management of patients with COPD.