Both chronic obstructive pulmonary disease (COPD) and asthma are characterised by the presence of airway inflammation. In the stable disease state, the predominant regulatory and effector cells, and the anatomic focus of the changes associated with airway inflammation, differ between COPD and asthma. However, during exacerbations, these patterns of inflammation become more similar. The benefit of anti-inflammatory therapy with inhaled corticosteroids (ICS) is well established in asthma, whereas the extent of the anti-inflammatory effects of ICS in COPD is debated. Understanding the distinctive and, in exacerbations, the changing patterns of inflammation in COPD and asthma allows a better appreciation of the potential for ICS to target the unique pathophysiology of COPD.