Quorum sensing (QS) controls systems affecting the pathogenicity of many microorganisms; its interruption has an anti-pathogenic effect and can be used in the treatment of bacterial infections. In this study we evaluated QS regulation by Pseudomonas aeruginosa strains and QS inhibition (QSI) by different compounds. The inhibitory activity of 3 macrolide and 3 lincosamide drugs, resveratrol, garlic extract and N-acetylcysteine was tested on 4 P. aeruginosa strains isolated from cystic fibrosis (CF) patients using Chromobacterium violaceum ATCC 12472 as biomonitor. One P. aeruginosa strain, lincomycin and N-acetylcysteine did not show QSI, contrary to other compounds and P. aeruginosa strains. These results indicate that QSI evaluation should be taken into account in the design of new therapeutic strategies to treat P. aeruginosa infections, especially in patients infected by antibiotic-resistant bacteria.