The National Asthma Education and Prevention Program is housed in the National Heart, Lung and Blood Institute (NHLBI) of the National Institutes of Health. To help health professionals care for people with asthma, the NHLBI convened panels of experts twice to prepare guidelines for the diagnosis and management of asthma. The first Expert Panel Report was released in 1991. The new 1997 guidelines are an evolutionary update of the initial 1991 report and are based on an improved understanding of the mechanisms of the disease and newer approaches to treatment. The recommendations are based on a review of more than 6000 scientific articles reviewed by the Expert Panel over the last 2 years. Four essential components of asthma management are described with new classifications of asthma severity and new guidelines for step therapy. The role of patient education in asthma management is emphasized in the report as well as the role of the primary care clinician and the expert consultant.