The National Centre for Antimicrobial Stewardship (NCAS) is a health services research program that aims to improve the use of antimicrobials across animal and human health, to influence national policy, and to generate a research workforce across nurses, pharmacists, doctors and veterinarians. NCAS aims to lead and facilitate the embedding of antimicrobial stewardship (AMS) within clinical practice across diverse healthcare settings and among different practitioner groups in Australia. Its research and surveillance programs aim to improve antimicrobial prescribing by understanding prescribing behaviours through qualitative and quantitative methods, monitoring current prescribing patterns across healthcare settings, identifying targets for quality improvement, and developing interventions, new policies and practices.