Objective: Review the molecular mechanisms of action, efficacy, and potential side effects associated with inhaled corticosteroids (ICS) in children with persistent asthma.Sources: Articles in English from MEDLINE. The following terms were used: corticosteroids, inhaled corticosteroids, asthma, children, beclomethasone, fluticasone, budesonide, ciclesonide, growth, adrenal insufficiency, bone mineral density, and oral candidiasis. Treatment guidelines, review articles, controlled trials, meta-analyses, and systematic reviews evaluating the efficacy and the adverse events of treatment with ICS were selected.Summary of the findings: In vivo and in vitro studies show that the available ICS have different pharmacokinetic and pharmacodynamic properties that result in different action potentials. ICS also differ as to the systemic and local side effects. The bioavailability of these products is essential in order to determine the incidence of side effects. In general, ICS are capable of controlling asthma, reducing the number of exacerbations, medical consultations, hospitalizations, and the need of oral corticosteroid (applications) bursts. Improvement can also be seen in pulmonary function, especially in patients with recent onset asthma. The most documented adverse effect is transitory decrease of growth rate.