This article discusses two projects that were aimed at enhancing the opportunities for professional development of the participants through collaboration between classroom teachers and teacher educators. The two projects, the Australian Project for Enhancing Effective Learning (PEEL) and the Canadian Learning Strategies Group (LSG), focused on the teaching and learning practices in secondary school classrooms. We examine those features that we contend have resulted in long-term sustainability and the success of these partnerships. An analysis of our own experiences and other empirical data from both projects illustrate our claims that these small-scale projects have: improved the learning environment in classrooms for students and teachers; created models of professional development for school and teacher educators; and provided valid knowledge about learning and teaching issues in classroom settings. The potential of such projects to achieve these aims depends upon: (a) a mutually held understanding of what types of classroom practices nurture good teaching and learning, (b) a setting where teachers have a strong commitment and control over the project and decide on its direction, and (c) a structure that allows teachers and teacher educators to meet regularly in an atmosphere of trust and mutual understanding.