This paper presents the findings of a multi-site case study focused on the role of mid-day supervisors in English primary schools. Ethnographic approaches were employed to gain an understanding of the role and how this is experienced by those who undertake it. This included a fully participatory phase where the researcher inhabited the role of a mid-day supervisor. Ethnographic interviews were also conducted. The research found that role strain, caused by a range of factors, as well as whether the role was legitimised or marginalised, had a significant impact on how the role was enacted and experienced by mid-day supervisors.