ObjectivesThe aim of this study was to generate new evidence on how The Daily Mile (TDM), a popular school-based running programme in the UK, is implemented in a diverse and multiethnic city in the UK and also the barriers faced by non-implementer schools.DesignMixed method cross-sectional study (including survey data collection and qualitative interviews).SettingPrimary schools in a multiethnic city in the East Midlands, UK.ParticipantsForty-two schools in Leicester city completed an online survey, and five teaching staff from five schools took part in follow-up semistructured qualitative interviews.ResultsOverall, 40.5% of schools who completed the survey reported having never implemented TDM, and 96.0% of implementer schools reported delivering TDM on three or more days per week. Reported barriers included space limitations and safety issues, timetabling and curriculum pressures, and pupil and teacher attitudes. Facilitators of implementation were teacher engagement and school culture/ethos, communication of the initiative and substantial delivery adaptations.ConclusionsThe findings from this study, based on data from schools in a multiethnic city in the UK, suggest that implementation of TDM is variable, and is influenced by a range of factors related to the school context, as well as the characteristics of TDM itself.