Introduction: “Red alert” pathogen this is how Acinetobacterbaumannii identified nowdays in healthcare facilities, due to its extensive antibiotic resistance pattern. Multidrug-resistant A. baumannii infections are best treated with Carbapenems. The aim of the study is to estimate the numbers of blaoxaand ISAba1 producing strains among carbapenem-resistant A. baumannii clinical isolates. Method: identification of A. baumanniiwas carried out by Matrix-assisted laser desorption ionization–time of flight mass spectrometry, VITEK 2 compact was used to assess antimicrobial sensitivities and E test used to reconfirm susceptibility to imipenem, multiplex PCR for class D β lactamase genes detection. Mapping PCR carried out in order toestimate the presence of ISAba1 in relation to blaOXA-23 and blaOXA-51 genes. Results: Fourty eight A. baumanniistrains were isolated from different anatomical sites from surgical patients in Zagazig University hospital. Antibiogram showed that 81.3% (n=39) of the isolates were resistant to Imipenem, while 9 isolates were susceptible (18.7%). Of 39 resistant isolates to Imipenem, ISAba1 was detected in 35 isolates (89.7%). 34 isolates carried blaOXA-23 gene, all contained ISAba1/blaOXA-23 genes, and 20 contained ISAba1/blaOXA-51 genes. Resistant isolates to carbapenemsall had ISAba1 upstream of blaOXA-23 gene, WhileISAba1 upstream of blaOXA-51 found in both susceptible and resistant isolates. Conclusion: The ISAba1/blaOXA-23 genes were prevalent among the carbapenem-resistant A. baumannii isolates and may be responsible forcarbapenems resistance. The present study revealed that the existence of ISAba1/blaOXA-51 in A. baumannii isolates was not conclusive to carbapenems resistance.