The main problem with any antibiotic therapies in cystic fibrosis is resistant bacteria’s infection, which makes many treatments ineffective. Therefore, the interest of researchers is moving to a new approach, no longer based on the killing of microbes through antibiotics, but rather aimed at disarming their pathogenicity, which is mediated by some chemical signals they produce. These chemical signals (i.e. Quorum Sensing) represent the language the bacterial species use to communicate, thus regulating the production of virulence factors. The project aims at developing new molecules capable of interfering with the Quorum Sensing of Pseudomonas aeruginosa (Pa) and other bacteria. Molecules’ testing will be at first performed in vitro; the most promising molecules will then be tested in P. aeruginosa strains isolated from CF patients. This is a new strategy with no immediate clinical impact, however very promising for future developments.