In the 1960s, asthma was defined as predominantly a disease of airway smooth muscle resulting in reversible airway obstruction and bronchial hyperresponsiveness. Early efforts therefore were aimed at reversing bronchospasm. It now is known that asthma is a chronic inflammatory disorder of the airways. The evolution of the treatment of asthma over the past two decades reflects an increased understanding of the crucial role of inflammation in asthma. This article discusses old and new strategies used in the treatment of chronic asthma in light of what is known regarding their pathobiologic effects (Table 1). Included are the following categories of therapeutic agents: β-Adrenergic receptor agonists, methylxanthines, corticosteroids, cromolyn, nedocromil, leukotriene modifiers, and investigational agents.