Traditional Chinese Medicine (TCM) postulates an interaction between the lung as a Yin-organ and the large intestine as a Yang-organ. The aim of this pilot study was to investigate in asthmatic school age children whether treatment with laser acupuncture and probiotics according to TCM portends a clinical benefit to standard medical treatment performed according to pediatric guidelines. Seventeen children aged 6-12 yr with intermittent or mild persistent asthma were enrolled in this randomized, placebo-controlled, double-blind pilot study. Eight patients received laser acupuncture for 10 wk and probiotic treatment in the form of oral drops (living non-pathogenic Enterococcus faecalis) for 7 wk. Nine patients in the control group were treated with a laser pen which did not emit laser light and were given placebo drops. Peak flow variability (PFV) and forced expiratory volume in 1 s (FEV(1)) were measured and Quality of Life was assessed by a standardized questionnaire. Laser acupuncture and probiotics significantly decreased mean (standard deviation) weekly PFV as a measurement of bronchial hyperreactivity by -17.4% (14.2) in the TCM group vs. 2.2% (22.5) in the control group (p = 0.034). No significant effect was detected for FEV(1), Quality of Life criteria and additional medication. As an exploratory result, patients in the TCM group had fewer days of acute febrile infections when compared with the control group [1.14 (1.4) vs. 2.66 (2.5), p = 0.18]. In conclusion, this pilot study generates the hypothesis that the interactive treatment of lung and large intestine according to TCM by laser acupuncture and probiotics has a beneficial clinical effect on bronchial hyperreactivity in school age children with intermittent or mild persistent asthma and might be helpful in the prevention of acute respiratory exacerbations. These results should be confirmed by further studies.