This paper explores power relations within a participatory health and social needs project that took place in a South Asian community in northern England. The project involved a number of different individuals and agencies, each of which began with a rather different combination of interests, agendas, resources, and power bases. Drawing on detailed observations made during the project, together with a series of evaluation interviews, we explore the ways in which these were continually re-negotiated, within a context of shifting power relations. We use a theoretical framework, derived from different interpretations of power and knowledge, and from Bourdieu's theories of cultural and symbolic capital, to unravel these processes of change. We find shifts in the balance of power over the course of a project are possible, but are often slow and rather limited, because of the self-perpetuating power of those holding symbolic capital to define and maintain the status quo. We conclude that community participation in health and social action research can never be a single event, but should be regarded as an ongoing, iterative process, which may extend far beyond the official bounds of the project itself.