Numerous clinical guidelines have been promoted to help improve the management of acute injury and illness. In November 1997, the National Asthma Education and Prevention Program released the final version of its comprehensive second Expert Panel Report, designed to distill scientific advances in asthma care and provide a set of practical tools to help guide clinician and patient decisions. The panel's recommendations for acute asthma care stress the use of the objective measures of pulmonary function to assess severity, aggressive inhaled beta 2-agonist therapy, early systemic corticosteroid administration, and early disposition decisions. This article provides a focused overview of the 146-page document and highlights aspects of the new guidelines of particular importance to emergency physicians.