Background Best practice guidelines recommend that a multidisciplinary Antimicrobial Management Team (AMT) conduct antimicrobial stewardship (AMS) activities in hospitals. In order to continuously improve AMS activities in Irish hospitals it is important to benchmark performance by comparison with other countries. Objective To compare the membership of AMTs and AMS activities conducted in Irish and United Kingdom (UK) hospitals. Methods A postal questionnaire to determine the membership and activities of AMTs was issued to the specialist antimicrobial pharmacist or pharmacist in charge at all Irish Hospitals and all UK National Health Service Hospitals. The membership of AMTs and the extent of AMS activities conducted were compared between the countries. Results The response rates to the surveys were 73 % (n = 51) in Ireland and 33 % in the UK (n = 273). 57 % of Irish respondents reported having an AMT compared to 82 % in the UK (p < 0.001). Significantly more AMTs in the UK had a specialist antimicrobial pharmacist on the team (95 % UK, 69 % Ireland, p < 0.001). A higher proportion of Irish respondents reported measuring the overall volume of antimicrobial prescribing (Ireland 85 %, UK 72 %, p = 0.057). A higher proportion of UK respondents reported measuring the appropriateness of antimicrobial prescribing (76 % UK, 58 % Ireland, p = 0.019) and the appropriateness of restricted antimicrobial prescribing (64 % UK, 52 % Ireland, p = 0.140). Conclusion Irish and UK AMTs need to be supported to recruit and retain specialist antimicrobial pharmacists and to achieve higher rates of audit, prescription appropriateness review and feedback activities.