The present study aimed to explore the genomic characteristics of eight New Delhi metallo-á-lactamase-1 (NDM-1)-producing carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates from a Bulgarian tertiary hospital (2021-2023) in comparison to blaNDM-1-positive strains originating from the Balkans. Antimicrobial susceptibility testing, phenotypic assays for carbapenemase activity, PCR screening, wholegenome sequencing (WGS), and phylogenomic analysis were performed. Seven of the CRPA isolates investigated (Minimum inhibitory concentration values of imipenem and meropenem >32 mg L1) were also resistant to piperacillin-tazobactam, ceftazidime, ceftazidime-avibactam, cefepime, ceftolozanetazobactam, amikacin, tobramycin, ciprofloxacin, and levofloxacin, but were susceptible to colistin (0.5-2mg L1) and cefiderocol (0.25-1mg L1). The P. aeruginosa Pae57 isolate (designated Pae57) remained susceptible to aminoglycosides as well. WGS uncovered the co-existence of blaNDM-1 and blaGES-1. The isolates belonged to the ST654 high-risk clone, except for Pae57 (ST611). Alignment against reference sequences revealed the presence of a Tn21 transposon harboring bleMBL-blaNDM-1-ISAba125. It was similar to that found in the P. aeruginosa ST654 NDM1_1 strain (GCA_020404785.1) from Serbia. Phylogenomic analysis of our isolates indicated that seven of them (ST654) differed from each other in no more than 44 single-nucleotide polymorphisms (SNPs). Pae57 (ST611) was strikingly different (>21,700 SNPs) compared to all Balkan strains. In conclusion, to our knowledge this is the first report of blaNDM-1-positive P. aeruginosa ST611 isolation, which indicates the transmission dynamics of this determinant between high-risk and potentially high-risk P. aeruginosa clones. Obtained results unveil the dissemination of clonally related NDM-1-producing P. aeruginosa strains in the monitored hospital for approximately a 2-year period. Kulcsszavak: carbapenem-resistant Pseudomonas aeruginosa, NDM-1 metallo-á-lactamase, high-risk clone, ST654, ST611, whole-genome sequencing, phylogenomic analysis, Balkans