This paper reviews new developments in bronchodilator therapy for chronic obstructive pulmonary disease (COPD). Most patients with COPD respond to bronchodilators, but we have no reliable way to predict which patients will respond. When responsiveness is assessed, changes in lung volume as well as improvements in FEV1 should be considered. The combination of a beta-agonist and an anticholinergic agent produces greater improvement than either agent alone. Anticholinergic agents have few adverse side effects in patients with COPD, but concern remains about the possible cardiac side effects of beta-agonists. No clear answer exists about whether new, long-acting beta-agonists, such as salmeterol, should supplant anticholinergic agents as "first-line" therapy in COPD.