Significance and Impact of the Study: This study shows, for the first time, the promising antimicrobial activity of phenanthroline derivatives against Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae clinical strains. It is interesting to highlight that, in addition to a significant antimicrobial effect, studied compounds also showed a strong ability in reduce meropenem minimal inhibitory concentration values of some strains to therapeutic levels (re-sensitization). We believe that we are facing to a group of compounds that should be explored from a therapeutic perspective since they have demonstrated, in previous studies from our research group, low toxicity in vivo and effectiveness against several other microbial species.