Introduction: Ceftazidime-Avibactam (CZA) is a β-lactam-β-lactamase inhibitor combination (BL/BLI) that has been given approval by the Food and Drug administration (FDA) for the treatment of different illnesses. However, resistance to Ceftazidime-Avibactam is developing in Carbapenem-resistant Enterobacteriaceae (CRE), Carbapenem-resistant Pseudomonas aeruginosa, and other Gram-negative bacteria, necessitating study of CZAs in vitro activity against these pathogens. Objective: To assess CZAs in vitro activity against CRE, carbapenem-resistant Pseudomonas aeruginosa, and other Gram-negative bacteria. Results: Of the 62 Carbapenem-resistant isolates obtained from various samples, Klebsiella pneumoniae accounted for 22 (35.48%), followed by Escherichia coli 21(33.87%), Pseudomonas aeruginosa 10(16.13%), Acinetobacter baumanii 7(11.30%), Citrobacter freundii 1(1.61%), and Proteus mirabilis 1 (1.61%) and the susceptibility rates against CZA showed Klebsiella pneumoniae-45.45% followed by E.coli-27.27%, Pseudomonas aeruginosa-18.18%, Citrobacter freundii-9.09% and the strains of A.baumanii and P.mirabilis were totally resistant to CZA. Conclusion: Even though CZA is regarded as an alternative form of treatment for infections caused by Carbapenem-resistant organisms (CRO), the higher resistance pattern at our center necessitates additional research involving numerous isolates and at different centers, where the results can be compared in order to ascertain the true prevalence of CZA resistance.