The Japanese herbal medicine Hochu-ekki-to (Chinese name: Bu-Zhong-Yi-Qi-tang) is composed of ten species of medical plants and is used for many therapeutic purposes such as recovery from weakness, dysfunction of the digestive system and fatigue. In certain groups of patients with intractable atopic dermatitis this prescription has shown clinical effectiveness. We examined the ability of Hochu-ekki-to to inhibit dermatitis and IgE production in atopic NC/Nga mice. Oral administration of Hochu-ekki-to suppressed spontaneous dermatitis and serum IgE levels in NC/Nga mice. This finding provides evidence that Hochu-ekki-to may have immunological effects in atopic dermatitis.