Exacerbations of chronic obstructive pulmonary disease (COPD) are usually treated with bronchodilator therapy, glucocorticoids and antibiotics. However, there are few experimental data on the effects of these agents in patients with acute COPD. A beta(2)-adrenoceptor agonist is usually given first because it can be expected to produce a rapid response. An anticholinergic agent should also be given when the patient is severely ill or responds inadequately to the beta(2) agonist. These agents can be administered via a nebuliser or using a metered-dose inhaler in conjunction with a spacer device. Glucocorticoids can accelerate recovery if the standard empirical regimens for acute exacerbations of asthma are used, although a longer treatment duration appears to be required. Theophylline provides little additional benefit in patients who receive frequent doses of inhaled bronchodilators and an adequate dosage of a glucocorticoid. Although the role of bacterial infections is not completely understood, the use of antibiotics is justified in patients with severe airflow limitation who have febrile tracheobronchitis.