The clinical value of corticosteroids in treating asthma has long been recognised. Major advances in the use of these drugs came with the introduction of inhaled corticosteroids (ICS) and the recognition that even mild asthma has an inflammatory component. ICS are now considered as first-line therapy in all asthma treatment guidelines. Over the past decade there has been clarification of the dose-response relationship with ICS and confirmation of the general long-term efficacy and safety of these drugs in both adults and children. Recent work has focused on simplifying dosing regimens and investigating flexibility of dosing. Moreover, ICS can be used in combination with other agents such as long-acting inhaled beta(2)-agonists to provide effective asthma control in patients with persistent asthma not adequately controlled on ICS alone. Thus, ICS remain the cornerstone of modern asthma therapy.