The development of potent glucocorticoids (GC) delivered topically via metered dose inhalers (MDI) have revolutionized the way we care for asthmatic children. Steroids can improve asthma symptoms, baseline pulmonary function, and reduce bronchial hyperresponsiveness (BHR) to the extent no other asthma medication can. In addition, the fact that small quantities of GC are delivered topically, the incidence of adverse effects is greatly diminished. Inhaled GC therapy has become first line therapy for all children even with mild persistent asthma, and their early use in life is known as "early intervention". The results from many studies suggest that the longer the time from the initiation of symptoms, and subsequent treatment with inhaled GC, the less effective this form of therapy may be. Also, early intervention and long-term therapy may offer the potential to effect long-term outcome. Unfortunately, systemic absorption does occur, and with that comes the potential for adverse effects. Growth suppression and bone metabolism effects remain the most feared, controversial, and inadequately addressed issues facing long-term inhaled GC therapy. In general, the development of adverse effects from inhaled GC therapy is dependent on the dose and the frequency with which the inhaled GC is given. They can also be minimized by using a spacer device, turbuhaler, mouth rinsing. It is important to define maximally safe and effective doses of the available inhaled GC and corresponding delivery systems.