Lecithin-bound iodine (LBI), which has been reported to be a potential candidate for one of the therapeutic modalities for children with bronchial asthma based on the in-vitro study, was also found to be effective in relieving the symptoms of patients with childhood asthma. In addition to the in-vitro effect of downregulation and upregulation of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma), respectively, the clinical effect of LBI was highlighted through the concomitant upregulation of IFN-gamma production by the patients' lymphocytes, which were treated with LBI for 8 weeks. Therefore, LBI may reduce the signs of bronchial asthma by upregulating the synthesis of IFN-gamma that is a representative Th1 cytokine.