AbstractCeftazidime/avibactam is an important option for the treatment of infections caused by multidrug‐resistant gram‐negative bacteria. Haematological abnormalities are rare adverse events. We describe a case of a 63‐year‐old male who developed severe neutropenia following exposure to ceftazidime/avibactam in the intensive care unit for the treatment of abdominal infections. Six days after ceftazidime/avibactam was prescribed, the patient experienced a sheer drop in absolute neutrophil count, down to a minimum of 0.13 × 109/L. A bone marrow examination showed neutrophilic maturation arrest. After careful screening of all drugs used by the patient and other potential causes of severe neutropenia, ceftazidime/avibactam was suspected to be the most likely culprit and was therefore replaced by cefoperazone/sulbactam, while a dose of colony‐stimulating factor was given. The next day, neutrophils rose to 3.64 × 109/L. To the best of our knowledge, this is the first case report of severe neutropenia associated with ceftazidime/avibactam. When neutropenia occurs during treatment, the clinician should keep this possibility in mind. Regular monitoring of neutrophil counts for timely recognition, immediate discontinuation of the drug and substitution of antibiotics are key steps in management.