The treatment of acute asthma exacerbation consumes a significant portion of emergency medical services (EMS) system resources. Because few studies have addressed EMS treatment of asthma, most EMS providers model their approach to treatment on strategies thought to be effective in the emergency department. During the treatment of asthma, a patient's history and current airway and respiratory status are important components of the initial assessment. Although the general evaluation may address a patient's appearance, vital signs, mental status, level of fatigue, and ability to speak normally, the initial assessment of an asthmatic patient must focus specifically on his or her respiratory effort and quality and on objective measurement of the patient's blood oxygenation. Inhaled beta-agonist therapy is the widely recommended first choice of treatment, but anticholinergic agents and steroids may also have roles. Although not routine treatments, parenteral magnesium and epinephrine may also be beneficial for certain patients. Endotracheal intubation is a procedure of last resort and should be reserved for patients at immediate risk of respiratory arrest. Finally, EMS providers must be alert to the danger of using a "treat and release" approach, as recommended by some protocols, in the treatment of acute asthma. The quick results and benefit that short-acting treatments provide can easily and erroneously lead a provider to believe that an attack has been adequately controlled when, in fact, a more serious exacerbation may be imminent. Treatment protocols, therefore, should discourage EMS personnel from this practice and advise them to always transport asthmatic patients they have treated to the hospital to undergo more extended care and monitoring.