This study evaluated the clinical efficacy of nebulized flunisolide nasal solution (Nasalide) in young children with moderately severe asthma. Twenty-two asthmatic children, ages 12-72 months, completed this double-blind placebo-controlled study. After a 6-week observation period, 18 patients were paired according to asthma severity. One child from each pair was randomized to flunisolide, the other to placebo; 4 patients were independently randomized. Placebo or drug was then administered for 6 weeks. Throughout the study, symptoms, drug usage, and analog scales reflecting asthma severity and family disruption were recorded in a diary. Multiple regression analysis was used to compare the flunisolide and placebo groups in regard to the amount of improvement demonstrated from the observation to the active periods of the study. Analog scores of asthma severity and family disruption, albuterol aerosol use, and systemic corticosteroid use fell roughly 40% from baseline in the flunisolide group. This improvement was significant compared to the placebo group. We conclude that 1 ml (250 microg) of nebulized flunisolide nasal spray solution, administered three times daily, reduced the severity of asthma symptoms, and the need for both albuterol aerosol and systemic corticosteroid therapy in young children with moderately severe asthma during a 6-week trial. Longer term studies are warranted.