This study examines the continuing professional development of one group of secondary school English language teachers who participated in a school-university partnership in Hong Kong. Grounded in a framework of teacher identity and using in-depth interviews conducted over the entire 12 month period of the partnership, the study explores the teacher's professional development experiences in terms of their negotiation of membership within and across multiple communities. Results suggest that the teachers' experienced professional development through partnership partly as identity conflict, as they negotiated recognition of the competencies they associated with the partnership within the different communities of teachers in which they participated. It is argued that such identity conflict can inhibit the opportunities for professional development that partnerships potentially offer teacher and schools and that a critical understanding of the contribution of partnerships to the professional development of teachers and other stakeholders within and beyond the partnership is necessary. (Contains 1 table and 1 figure.)