Airway inflammation is assumed to be an important determinant in increased bronchial responsiveness (BR). We tested the hypothesis that treatment with an inhaled anti-inflammatory drug (i.e., budesonide) but not with an inhaled beta-agonist (i.e., terbutaline) would reduce BR in children with asthma and with minimal or no bronchoconstriction. Twelve patients were treated with budesonide and seven with terbutaline for 6 months. BR decreased in 11 patients receiving budesonide and was significant in seven patients. BR decreased in none of the patients receiving terbutaline. FEV1 demonstrated a small increase with budesonide but remained unchanged with terbutaline. Except in one patient who received terbutaline, the clinical effect was good. We conclude that inhaled corticosteroids but not inhaled beta-agonists will decrease persistent BR in most children with asthma.