COPD is characterized by a not fully reversible airflow limitation which is progressive and associated with an abnormal inflammatory reaction of the lungs. Airflow limitation is most often assessed by FEV (1.0). However, FEV (1.0) does not always reflect the course of the disease and does not appropriately describe the functional effect of a pharmacological or non-pharmacological intervention. Measurement of inspiratory parameters, e.g. IC or FIV (1.0), as well as assessment of exercise capacity should therefore be part of functional tests. The abnormal inflammatory reaction of the lungs can be assessed by a variety of methods. However, the characteristic increase of the number of neutrophils does not indicate a new therapeutic target. The term abnormal inflammation of the airways in bronchial asthma as well as in COPD presumably prompted a number of studies investigating the effects of inhalative corticosteroids in COPD. ICS do not alter the course of the disease, however they may reduce the number and severity of exacerbations. Combination of long-acting beta -agonists and ICS exert a better effect than either compound alone. This beneficial effect is difficult to explain by an anti-inflammatory action, as the long acting anticholinergic tiotropium has a comparable symptomatic and functional effect and reduces exacerbations without any known anti-inflammatory component. Future pharmacological therapies should therefore be based on a better understanding of the functional consequences of the disease and its pathogenesis.