Recent studies have demonstrated that it is possible to reduce allergic diseases in subjects "at risk" for atopy through the adoption of particular dietetic-environmental manipulations in the first few months of life. We have followed-up prospectively 174 infants, children and/or brothers of atopics, born at San Giovanni Calibita Hospital of Rome. In all cases, exclusive breast feeding for the first 6 months of life was recommended, with integration/replacement with soy milk (Isomil, Abbott), delayed weaning beyond the 6th month of life and rigorous hygienic environmental manipulation. The low prevalence of atopic disease (10%) and the absence of serious allergic manifestations in this "at risk" population confirms the advantage of such preventive programs.