This research was conducted in the light of the Every Child Matters (Department for Education and Skills, London, 2003) agenda which highlights the importance of multi-agency working. The research explored the professional identity of Educational Psychologists (EPs) with experience of multi-agency working in six Local Authorities within the Midlands area. Ten EPs participated in detailed semi-structured interviews. Activity Theory was used to facilitate the comparison of aspects of the EPs' two work roles, as part of the Educational Psychology Service (EPS) and as part of a multi-agency team (MAT). Each EP was asked to consider different elements of their two roles, using a series of questions designed to elicit relationships between the ways in which they worked, the contexts and the other people involved. From these questions, issues of professional identity emerged and these were then explored in more detail. The experiences of EPs working in MATs were generally described very positively. It appeared that multi-agency working enhanced feelings of professional identity. In some cases participants indicated that this was aided by the clarification and development of their own skills and in other cases by being afforded the opportunity to work creatively in a wider range of contexts. The flexibility of multi-agency working appears to have presented opportunities for individuals to work to their strengths and increased positive feelings EPs have of their own professional identity. (Contains 3 tables.)