A wide range of topics can be included under the heading of recurrent infections in children. This discussion focuses on 1) the definition of recurrent infection and physiopathogenetic mechanisms predisposing to; 2) controversies in the management of upper respiratory tract infections; 3) recurrent upper and lower respiratory infections in immunocompromised hosts, emphasizing advances in diagnosis and treatment of "mild" immunodeficiencies such as IgG subclass deficiency or antibody deficiency in normogammaglobulimia, trying to define an operative flow chart.