In childhood recurrent respiratory infection with Moraxella catarrhalis have high incidence demonstrated by multiple risk factors association (atopia, immunsuppresion, chronic diseases, malnutrition) that makes this common bacteria pathogen. The study was carried on 56 children (0-16 years old). Authors try to find correlations between clinical signs and microbiological markers that determine recurrent respiratory infection with Moraxella catarrhalis. Treatment consisted of association between "target" antibiotherapy and immunomodulation drugs. Efficacy of this treatment was proven by decreased numbers of recurrent infection (in 35% cases comparing to 53% selected cases for immunomodulation), improvement of evolution of chronic diseases, decreased number of days and price of hospitalisation.