Inhaled corticosteroids are a first-line therapy for persistent asthma in children. Major safety concerns of long-term inhaled corticosteroid therapy include suppression of adrenal function, growth and bone development. Proper interpretation of inhaled corticosteroid safety studies requires knowledge of the differences among various inhaled corticosteroid drug/delivery device systems. Dosage, type of inhaler device used, patient technique and characteristics of the individual drug influence the systemic effects of inhaled corticosteroids. Systemic side effects can occur when continuous high-dose treatment is required for severe asthma or when the dosage prescribed is excessive and compliance unusually good. Overall, however, recent studies confirm that benefits of inhaled corticosteroids, properly prescribed and used, clearly outweigh not only their potential adverse effects, but also the risks associated with poorly controlled asthma.