The use of systemic and inhaled corticosteroids for COPD has increased appreciably over the past 20 years. Clearer indications for corticosteroid therapy in COPD are beginning to emerge as the results from large clinical trials become available. Systemic corticosteroids are only modestly effective for acute COPD exacerbations, increase the risk for hyperglycemia, and should be given for no more than 2 weeks. The efficacy of long-term systemic corticosteroid therapy has not been adequately evaluated in this patient population. If longer term use of systemic steroids in COPD should be found to be useful, this conclusion would have to be weighed against the risk for serious adverse effects. High doses of inhaled corticosteroids cause a small sustained increase of the FEV1 in patients with mild and moderately severe COPD, but they do not slow the rate of FEV1 decline. Based on analyses of secondary outcome, inhaled corticosteroids may improve the respiratory symptoms and decrease the number and severity of COPD exacerbations in patients with more advanced disease. Low doses of inhaled corticosteroids appear to be safe, but there is growing awareness that higher doses may not be so benign.