This article presents the findings from research conducted at nine schools (seven primary, two secondary) in England, which had previously implemented a peer mediation service for students experiencing interpersonal conflict. This analysis was informed by themes from a previous stage of research conducted at one additional primary school, where the process from pre- to post-intervention had been observed in greater detail. The article utilises activity theory as a conceptual framework for understanding and describing these processes for a number of reasons that will be briefly explained. The findings of this research highlight the need for realistic anticipation of the degree of cultural transformation required to fully support such pupil empowerment initiatives in schools. Peer mediation was most successful in schools where there was a considerable shift in the division of labour, accompanied by the production of new cultural tools that promoted new ways of thinking, speaking and acting with regard to conflict.