The aim of this study was to evaluate the efficacy of traditional Chinese acupuncture in patients with mild asthma. The method used for evaluation of efficacy was total airway resistance at 5 Hz (R₅) as measured by impulse oscillometry (IOS) – a forced oscillation technique – at baseline and after a bronchial challenge with voluntary isocapnic hyperventilation of cold air (IHCA). The study was a parallel group, randomised, placebo-controlled trial with evaluator blinding. Twenty-seven patients were recruited and 24 completed the study: 10 of them received acupuncture and 14 received a placebo treatment (mock-TENS). Treatment continued for 15 weeks, and efficacy was tested 2 weeks following the last treatment. There were no statistically significant effects of the treatment before or after IHCA in either group. The authors concluded that there were no significant effects of traditional Chinese acupuncture on airway status in patients with asthma.