This study is designed to investigate the impact of school-based curriculum development teams on teacher development within the tradition of school-based curriculum development in a primary school in Hong Kong. Teacher interviews were used to evaluate the extent that teacher engagement in curriculum decision-making processes within two school-based curriculum development teams has led to teacher professional development which were triangulated with the videotaped meetings and tryout lessons. Qualitative evidence has revealed positively that participating teachers have developed themselves professionally through the process of planning, experimenting and reflecting (PER model) upon curriculum practice and innovation under certain conditions. However, the complexity of the structures and processes that were established for involving teachers in curriculum decision-making processes needs further empirical and theoretical work. This paper only looks at data relating to teacher development in curriculum leadership collected in the second action cycle of the project from January to June 2005. [Copyright of Asia-Pacific Journal of Teacher Education is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/13598660701268569]