Clinical experience with ceftazidime-avibactam (CAZ-AVI) for the treatment of carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections is not well evaluated. The aim of this study was to assess its efficacy in a single-centre cohort of patients infected with CR-KP.We conducted a retrospective observational study of consecutive patients treated for >72 h with CAZ-AVI or other active antibiotics (OAAs) for CR-KP infections. The primary outcome was 30-d mortality. The secondary outcomes were 14-d clinical failure and 14-d microbiological failure. Multivariate regression and propensity score matching were used to evaluate the relationship between CAZ-AVI treatment and outcomes.Ninety infections caused by CR-KP were documented in our study. Forty-two patients were treated with CAZ-AVI and 48 with OAAs. The crude 30-d mortality (8/42 vs. 22/48, P=0.007), 14-d clinical failure (14/42 vs. 24/48, P=0.046) and 14-d microbiological failure (11/42 vs. 15/48, P=0.034) were significantly lower in patients with CAZ-AVI treatment. The Kaplan-Meier survival curves of 30-d mortality confirmed the findings (logrank=0.004). In the multivariable models, the odds ratio (OR) of 30-d mortality (OR 0.23 95% CI 0.10-0.51, P5, OR 0.13, 95% CI 0.04-0.36, P3, OR 0.15, 95% CI 0.04-0.55, P=0.004). After propensity score matching, 29 cases from each group were well matched. The 30-d mortality remained significantly lower in the CAZ-AVI group (6/29 vs. 13/29, P=0.05).CAZ-AVI may be a more valuable therapeutic option for severe CR-KP infections than for mild cases and further randomized controlled trials are needed to evaluate the efficacy.