Persistent and dysregulated inflammation, combined with an exaggerated host response is a major contributor to CF lung disease. As lung disease progresses, neutrophil accumulation in the airways ensues. Modulation of CF airway inflammation may result in either beneficial or deleterious side effects, resulting in more harm than good. Antibiotics, in particular, macrolides which act as a long-term anti-inflammatory agent with an excellent safety profile, and dornase alpha, are very interesting agents; steroids are not indicated in CF except in very special situations, and other promising agents such as leukotriene modifiers, high-dose N-acetylcysteine, anti-elastase and anti-cytokines require further research. Research should focus on early treatment, before lung damage has occurred.