The appropriate use of anticholinergic bronchodilating agents in the management of patients with chronic obstructive pulmonary disease (COPD) or asthma is the subject of renewed academic interest. This article examines the physiology of airway function and the pharmacology of anticholinergic agents, and reviews the relevant clinical literature concerning the use of these agents for individuals with chronic obstructive pulmonary disease or asthma. It is suggested that anticholinergic bronchodilators are safe and effective as first-line therapy for COPD and should be considered as adjunctive therapy for asthma.