This article presents a study exploring the beliefs, knowledge, and practices of four middle and secondary science teachers participating in a collaborative curriculum action research project. Using a case study methodology, the views and practices of these teachers were described and analyzed as they investigated novel ideas about scientific inquiry and nature of science, critically examined their practice, and implemented and reflected upon modified curricular practices. Findings indicated that by the end of the study, all participants had enhanced their views of scientific inquiry and nature of science, and the collaborative group evolved as a community of teachers. Wenger's (1998a) community of practice theory provided a useful framework to describe and analyze the experiences of these science teachers. Implications for the professional development of science teachers and the compatibility between a community of practice and collaborative action research projects are presented.