Abstract. Objectives: Recent work in bronchiolitis has demonstrated a significant clinical improvement in children treated with epinephrine over nebulized salbutamol. The objective of this study was to determine whether nebulized epinephrine, as compared with nebulized salbutamol, causes a greater clinical improvement in children with acute asthma. Methods: Children, aged 1 to 17 years, with acute asthma presenting to the emergency department (ED) were eligible. In this double-blind study, patients were randomly allocated to receive either salbutamol or racemic epinephrine by nebulization at 0, 20, and 40 minutes. All patients received oral steroids. The primary outcome measure was a change in pulmonary index score (PIS). Results: One hundred twenty patients were randomized. The groups were comparable in terms of age, gender, asthma severity, previous treatments, and use of inhaled steroids. There was no significant difference between treatments in the change in PIS, length of stay, admission to hospital, or relapse rate. The epinephrine-treated group had significantly more minor side effects (such as excess or brownish nasal discharge). Conclusions: There is no significant clinical benefit of nebulized epinephrine over salbutamol in children 1-17 years old with mild to moderate acute asthma. Salbutamol remains the treatment of choice in children with known asthma.