In the current study carbapanem-resistant P. aeruginosa bloodstream infection (CRPA-BSI) was associated with high 14-day mortality. Although, highly resistant to meropenem, half of the isolates achieved in vitro synergy with the combination of meropenem with colistin, and the patients that received this combination therapy showed a tendency towards lower mortality. Our strains did not carry exo U gene, on the other hand, patients with CRPA-BSI caused by strains harboring gene las B evolved more frequent to death.