During the last decade infections caused by MDR Gram-negative bacteria (GNB) have become increasingly prevalent. Because of their high morbidity and mortality rates, these infections constitute a serious threat to public health worldwide. Ceftazidime/avibactam is a new approved agent combining ceftazidime and a novel β-lactamase inhibitor with activity against various β-lactamases produced by MDR GNB. Avibactam has a spectrum of inhibition of class A and C β-lactamases, including ESBLs, AmpC and Klebsiella pneumoniae carbapenemase (KPC) enzymes. Thus, combination with this inhibitor expands ceftazidime's spectrum of activity to MDR Enterobacteriaceae and Pseudomonas aeruginosa strains. In Phase II clinical trials of patients with complicated intra-abdominal infections and complicated urinary tract infections ceftazidime/avibactam exhibited clinical efficacy comparable to those of meropenem and imipenem/cilastatin, respectively. A Phase III clinical trial confirmed the efficacy of ceftazidime/avibactam in patients with MDR Enterobacteriaceae and P. aeruginosa infections. Microbiological surveillance studies, in vivo animal models of infection and pharmacokinetic/pharmacodynamic target attainment analyses are also discussed, to assess the potential role of this new drug in the treatment of infections caused by MDR GNB.