A randomized clinical trial comparing subcutaneous epinephrine and terbutaline injections was conducted in asthmatic children at The Methodist Hospital, Brooklyn, New York. Clinical evaluation using the Asthma Scoring System was done at baseline and serially, every 15 minutes, following injection of either drug. Reversal of wheezing, and changes in respiratory and heart rates were assessed using strict a priori criteria. The patients' differential response to both drugs was assessed by a crossover study when the same patients came subsequently for another episode of wheezing. Our results show terbutaline to be more efficacious at a dose comparable to epinephrine dose.