Initiatives to bring about school improvement usually involve certain teachers taking on leadership roles. This paper presents findings of a study that examined the experiences of a small group of teacher leaders in schools that have demonstrated successful school improvement. The schools participated in a school-improvement project in England, conducted by a team of tutors at the University of Cambridge Institute of Education. The project, Improving the Quality of Education for All (IQEA), was based on shared decision making and school autonomy to enhance the work of teachers and to improve student outcomes. Data were obtained from interviews with a total of eight teacher leaders from four IQEA schools that demonstrated successful change. Findings illustrate the idea that change is learning--not so much as a metaphor about change, but as a reality for teachers managing change. These teachers were contributing to the development of professional learning environments in their respective schools. The teachers engaged with three closely integrated levels of activity within their schools. First, they strove in diverse ways to change, deepen, and broaden their own and their colleagues' perceptions of their schools. Second, as organizational structures and staff dynamics changed, the schools' cultures changed, leading to a productive blend of collegial challenge and support. Third, the collaborative culture facilitated professional learning. In conclusion, there is a need to develop more specific change strategies to help teachers interpret overall school improvement in terms of their own practices. (LMI)