In a retrospective analysis of our patient population, 20 difficult-to-treat patients with asthma were found to have clinical and laboratory evidence of specific antibody deficiency, and several had mild hypogammaglobulinemia. Intravenous immunoglobulin replacement therapy at 400-600 mg/kg every 3-4 weeks gave remarkable clinical benefits, with reduction in morbidity, number of hospitalizations, steroid therapy, and number of respiratory infections. We believe that, in this group of patients, the use of intravenous immunoglobulin perhaps allows the achievement of asthma prevention rather than an amelioration of inflammation.