Short courses of systemic corticosteroids are indicated in the treatment of moderate and severe asthma exacerbations as well as mild exacerbations unresponsive to increased doses of β-agonist therapy and inhaled corticosteroids. Prednisone (1 to 2 mg/kg daily for 5 days) and dexamethasone (0.3 to 0.6 mg/kg daily for 1 to 5 days) are appropriate choices, with some evidence suggesting that dexamethasone might be better tolerated and requires shorter duration of therapy. Side effects of short corticosteroid treatments appear minimal and clinically insignificant. More studies are needed to ascertain the optimal dose, duration, and choice of systemic steroids, especially in the ambulatory care setting.