A double-blind study was carried out in 20 asthmatic children in order to evaluate the therapeutic efficacy and safety of inhaled corticosteroid flunisolide. 0.5 mg of the drug was administered by a jet nebulizer twice daily for 2 months. Respiratory symptoms, pulmonary function values and methacholine PC20-FEV1 were evaluated, as also morning cortisol levels, plasma cortisol increase after ACTH test, and 24-h urinary cortisol excretion. The data obtained show the efficacy of the drug in reducing symptoms. No significant difference was observed in pulmonary function values and in bronchial reactivity results between the two groups. No effect of flunisolide was observed on hypothalamic-pituitary-adrenal function. This study confirms the efficacy and safety of flunisolide (0.5 mg b.i.d.) in the treatment of asthmatic children.