Introduction: Gram-negative sepsis remains one of the most difficult to treat infections in intensive care units (ICUs). Carbapenems are often considered to be robust and reliable options for treating infections due to Gram-negative bacteria. The dominance of carbapenem-resistant enterobacteriaceae (CRE) has emerged as one of the greatest challenges faced by the medical community today. Carbapenem-resistant enterobacteriaceae may be resistant to all beta lactam antimicrobials including carbapenems and often, are even resistant to other classes of drugs. There are limited studies comparing polymyxin-based therapies with ceftazidime-avibactam (CAZ-AVI)-based therapies for treating infections caused by CRE. Methods: A retrospective study comparing outcomes between patients with bacteremia caused by CRE treated with polymyxin-based combination therapy and CAZ-AVI-based therapy (with or without aztreonam). Results: Of total 104 patients, 78 (75%) were in the CAZ-AVI group. There was no significant difference in the underlying comorbidities between the two groups. The incidence of nephrotoxicity was significantly higher in the polymyxin group (p = 0.017). Ceftazidime-avibactam-based therapy was 66% less likely to be associated with day 14 mortality (p = 0.048) and 67% less likely to be associated with day 28 mortality (p = 0.039) as compared with polymyxin-based therapy. Conclusion: Ceftazidime-avibactam-based therapy may be a superior option to polymyxin-based therapy for infections caused by CRE. This can have significant practical applications, in terms of optimizing therapy for the individual patient as well as sparing polymyxins and reducing the use of polymyxins in our hospitals.