Iron uptake is a vital process for all living cells, including CF pathogens, hence it represents a vulnerable target for novel antibacterials. Ga(III) has the ability to inhibit bacterial growth by disrupting iron metabolism, acting as iron mimetic. Two clinical trials are in progress to test the efficacy of Ga(III) in CF patients. Preliminary results of FFC#21/2015 project showed that the antibacterial activity of Ga(III) can be potentiated by suitable ligands having a structure similar to iron carrying molecules (siderophore); moreover, P. aeruginosa CF isolates were shown to be more susceptible to Ga(III), compared with laboratory strains or strains from systemic infections. The main goals of this one-year extension project are i) to comparatively evaluate the antibacterial activity of Ga(III) complexes/formulations against major CF pathogens; ii) to investigate the toxicology and pharmacokinetics of the Ga(III) complexes/formulations; iii) to improve the synthesis of Ga(III) carriers derived from pyochelin (PCH) siderophore structure. The final objective is to identify new Ga(III) formulations endowed with more potent antibacterial properties, high bioavailability, low toxicity and suited for aerosol administration, hopefully, ready for clinical testing.