Chronic obstructive pulmonary disease (COPD) is a serious illness that affects over 5% of the adult population. It is one of the few conditions for which the mortality and morbidity are still increasing. Experts expect COPD to become the third leading cause of death and the fifth leading cause of disability worldwide by the year 2020. Thus far, the only treatments that have been shown to make a difference to survival are smoking cessation and the use of oxygen supplements for those who are hypoxaemic at rest. The use of inhaled corticosteroids as monotherapy or in combination with a long-acting beta2-adrenoceptor agonist for COPD is controversial. Experimental data indicate that the inflammatory process in COPD may be resistant to the anti-inflammatory effects of corticosteroids. However, several large clinical studies have shown that inhaled corticosteroids in relatively high doses (e.g. budesonide 800 microg/day or fluticasone propionate 1 mg/day) reduce exacerbations by 20-30% and improve the health status of COPD patients by a similar amount compared with placebo. Withdrawal of inhaled corticosteroids may increase clinical exacerbation rates by 50% in COPD patients and by 2-fold in those with severe disease. Combined therapy with inhaled corticosteroids and long-acting beta2-adrenoceptor agonists may be superior to individual component therapy in reducing exacerbations. However, these medications must be used cautiously, as they have been associated with certain adverse effects. Inhaled corticosteroids, for instance, increase the risk for dysphonia and oral thrush by 2- to 3-fold. Skin bruising is also more common in users than in non-users of inhaled corticosteroids. On balance, for those with moderate-to-severe COPD and those who experience frequent exacerbations, judicious use of inhaled corticosteroids alone or in combination with long-acting beta2-adrenoceptor agonists appears reasonable.