Effective pre-service teacher education integrates theoretical and practical knowledge. One means of integration is practicum in a school workplace. In a time of variable approaches to, and models of, practicum, we outline an innovative model of school immersion as part of a teacher preparation program. We apply Fuller and Unwin's (2004) expansive and restrictive conceptual framework of workplace learning to a case study of an immersive practicum experience to discuss themes of participation, personal development and institutional arrangements in relation to school-based practicum. Enablers and constraints are identified for our immersion model of workplace-based practicum. Based on the data analysis a number of implications for structuring an expansive practicum learning experience are outlined. (Contains 4 tables.)