Inhaled corticosteroids are the first-line therapy for persistent asthma in children. Major safety concerns of long-term inhaled corticosteroid therapy include suppression of adrenal function and impaired growth and bone development. Proper interpretation of inhaled corticosteroid safety requires knowledge of differences among various drug devices. Dosage, type of inhaler device used, patient technique, and characteristics of the individual drug influence systemic effects of inhaled corticosteroids. Systemic side effects can occur when continuous high-dose treatment is required for severe asthma or when prescribed dosage is excessive and compliance is unusually good. Recent studies confirm that benefits of inhaled corticosteroids outweigh potential adverse effects and the risks associated with poorly controlled asthma.