Albuterol, a new bronchodilator drug known to cause .beta.2-adrenergic receptor stimulation, was compared with isoproterenol sulfate for pulmonary and cardiovascular effects in patients suffering from bronchial asthma. In a double-blind manner 24 patients received as aerosol 170 .mu.g of albuterul or 150 .mu.g of isoproterenol or placebo on 3 different days. Spirometric, plethysmographic, heart rate and blood pressure measurements were made at 1, 5, 15, 30, 60, 90, 120, 300 and 360 min after drug inhalation. Baseline values for various indices we not significantly different before drug administration. Albuterol was an effective bronchodilator, and its bronchodilating effect was significantly superior and of longer duration than that of isoproterenol. Albuterol did not produce any significant changes in blood pressure and pulse rate, thus confirming its selectivity for .beta.2 receptors.