Three subcutaneous doses of 0.3 mL 1:1,000 epinephrine were given 20 minutes apart to 95 adult asthmatics 15 to 96 years old during 108 asthma exacerbations. Patients with a history of recent myocardial infarction or of angina were excluded from our study. Heart rhythm and rate, blood pressure, respiratory rate, and clinical response were prospectively evaluated before, during, and after the administration of epinephrine. There was no significant difference in the occurrence of ventricular arrhythmias between patients less than 40 and more than 40 years old. The mean systolic and diastolic blood pressures, mean heart rate, and mean respiratory rate decreased with treatment in the older population. Our results suggest that epinephrine is safe to use in acute asthmatics of any age.