Exacerbations are an important cause of the morbidity and mortality associated with asthma and chronic obstructive pulmonary disease. Newer therapies include long-acting beta(2)-agonists, which are more effective than short-acting bronchodilators. Inhaled corticosteroids and, in asthma, leukotriene receptor antagonists may have roles in the early phase of exacerbation as an alternative to or added to oral prednisolone. In the future, combinations of long-acting beta(2)-agonists and anticholinergic bronchodilators may offer additive clinical benefits. However, although the treatment and prevention of exacerbations of chronic obstructive pulmonary disease and asthma have been improved by using combinations of known therapies, further research addressing the underlying etiology as well as molecular and pathophysiologic mechanisms of exacerbation is needed to better target novel therapies to the appropriate patient populations and to develop new therapeutic strategies.