Systemic corticosteroid therapy for patients with exacerbations of chronic obstructive pulmonary disease has become increasingly commonplace over the past two decades. This practice was controversial because a number of small clinical trials provided inconclusive evidence about efficacy. Experience from recent trials indicates that systemic corticosteroids are modestly effective in this setting. Systemic corticosteroids administered to hospitalized patients reduces the absolute treatment rate by about 10%, increases the forced expiratory volume in 1 second (FEVl) by about 100 mL, and shortens the hospital stay by 1 to 2 days. Treatment should not extend longer than 2 weeks. The optimal starting dose is not known. Hyperglycemia and possibly an increased rate of secondary infections are expected complications of treatment.