Cystic fibrosis (CF) affects between 1in 2000 and 1 in 4500 births in caucasians of European descent. It is caused by a defect in the cystic fibrosis transmembrane conductance regulator (CFTR) resulting in abnormal membrane osmolarity. CF is a multi-organ disease, however the cause of death is most often due to respiratory failure caused by infection of the airway epithelia with the bacterium Pseudomonas aeruginosa. Ps. aeruginosa grows in the airways as a biofilm and is recalcitrant to treatment with antibiotics. Therefore alternative therapies are urgently required. Bacteriophages have been and still are used in ex-Soviet bloc countries as a treatment for many infections. However, to date very few comprehensive studies have been conducted into phage therapy in humans. The aim of this study was to characterise several Ps. aeruginosa phage and to develop an in vitro co-culture model simulating a Ps. aeruginosa lung infection on which bacteriophage could be assessed for their efficacy as a therapeutic agent.