Most asthma exacerbations require immediate care, close observation for deterioration, frequent treatment, and repeated measurement of lung function. The NAEPP Expert Panel recommends that all clinicians treating asthmatic patients should be prepared to treat an asthma exacerbation, recognize the signs and symptoms of severe and life-threatening exacerbations, and be familiar with the risk factors for asthma-related death. Because infants are at greater risk for respiratory failure, clinicians should also be familiar with special considerations in the assessment and treatment of infants experiencing asthma exacerbations. All patients presenting with an asthma exacerbation should be evaluated and triaged immediately, with treatment instituted promptly on determination of a moderate, severe, or life-threatening exacerbation. Primary treatment consists of administration of oxygen, inhaled β2-agonists, and systemic corticosteroids, with the dose and frequency of administration, along with the frequency of patient monitoring, dependent on the severity of the exacerbation. After treatment and repeat assessment, patients can generally be discharged if FEV1 or PEF results are 70% or more of predicted value or personal best and symptoms are minimal or absent. Before discharge, patients should be prescribed 3 to 10 days of corticosteroid therapy to reduce the risk of recurrence and provided with a follow-up appointment to evaluate the need for additional corticosteroid treatment. Clinicians should consider (conditional recommendation) initiating inhaled corticosteroids. Patients should also be educated on correct use of the inhaler and should be given a written discharge plan for increasing medications or seeking care in the event of worsening asthma. © 2009 American Academy of Allergy, Asthma & Immunology, American Thoracic Society, and Elsevier Inc.