In a double-blind (patient and evaluator), crossover study effects of real acupuncture, simulated acupuncture, nebulized isoproterenol, nebulized saline and no treatment in reversing methacholine-induced bronchospasm were compared in 12 asthmatics (ages 16 to 64). Saline and simulated acupuncture did not result in any significant improvement in specific airway conductance (SGaw), thoracic gas volume (Vtg) or forced expiratory flow rates compared with no treatment following methacholine-induced bronchospasm. Isoproterenol and real acupuncture were both followed by increases in SGaw and flow rates and decreases in Vtg which were significantly different from the changes observed following no treatment, saline or simulated acupuncture, although isoproterenol produced greater improvement than real acupuncture, although isoproterenol produced greater improvement than real acupuncture. These findings suggest that stimulation of specific acupuncture loci reduces methacholine-induced bronchospasm and hyperinflation to an extent greater than can be attributed to placebo phenomena.