Immunoglobulin E (IgE) plays a central role in the pathogenesis of allergic diseases. Cross-linking of IgE molecules on mast cell and basophil surface membrane by allergens, triggers the release of multiple mediators, leading to the development of IgE-mediated immediate and late hypersensitivity reactions. In view of the pivotal role of IgE, it became an attractive target for intervention in the treatment of allergic diseases. Murine monoclonal non-anaphylactogenic antibodies directed to the receptor-binding domain of IgE, were found to reduce IgE levels and production. Anti-IgE antibodies have been recently evaluated in several clinical trials involving hundreds of asthmatic patients both adults and children, including patients with allergic rhinitis. Clinical efficacy and good tolerability were demonstrated. This novel therapeutic approach also appears to be promising for potential treatment of patients suffering concomitantly from several allergic disorders.