To evaluate the effect of nebulized budesonide on acute, young, wheezing patients, a total of 73 patients, aged below 24 months, who were hospitalized due to bronchiolitis were randomly enrolled into this study according to age. They were divided into four groups and treated with four kinds of nebulized solutions. Group I consisted of 18 patients under 12 months old who were treated with budesonide (1 mg/2 ml) diluted with 2 ml isotonic sodium chloride. Group II consisted of 18 patients under 12 months old who were treated with 4 ml isotonic sodium chloride. Group III included 16 patients between 12 and 24 months old who were treated with terbutaline (5 mg/2 ml) diluted with 2 ml isotonic sodium chloride. Group IV included 21 patients between 12 and 24 months old who were treated with budesonide (1 mg/2 ml) and terbutaline (5 mg/2 ml). Clinical data on respiratory rate, wheezing score, cyanosis score and accessory respiratory muscle utilization score were recorded in all patients before and after treatment throughout the entire hospitalization. The results of this study showed no benefits from nebulized budesonide in infants with bronchiolitis either younger than 12 months old or between 12 and 24 months of age. The duration of admission also showed no significant differences among the groups.