Bronchopulmonary infection determines the vital prognosis of the patients with cystic fibrosis. Following Staphylococcus aureus infection, patients are colonized or cocolonized by Pseudomonas aeruginosa, greatly involved in the pulmonary deterioration; intensive antibiotic treatment of primocolonisation helps to prevent or delay chronic colonisation. Chronic colonization needs a rational long term antibiotic strategy to prevent the occurrence of multiresistant germs; antibiotic cures are performed every 3 or 4 months before pulmonary exacerbation symptoms. Antibiotherapy, physiotherapy and nutritional management helps to increase the survival and quality of life.