Inflammation plays a major role in the pathophysiology of lung disease in CF. This response is probably triggered primarily as a reaction to the inability of the affected lung to resist the invasion of the most common bacterial pathogens seen in this disease, namely, Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa. Debate continues as to whether there may or may not be a pre-inflammation of the lungs as part of the basic functional defect of CFTR. The anti-inflammatory treatment modalities most tested to date are: oral corticosteroids, effective but associated with significant long-term side effects, inhaled corticosteroids, so far not proven to be effective probably because of difficulty with absorption through the viscid surface secretions of the lung and ibuprofen, potentially effective but inhibited by the need to monitor drug levels invasively and potential gastrointestinal side effects. The most promising newcomer is macrolide antibiotics such as azithromycin acting as a long-term anti-inflammatory agent with an excellent safety profile.