Identity is a complex construct, yet extremely important if we wish to understand the practice of teaching as a profession. In this paper, we examine the ways two middle school teachers talk about their identity and teaching practices and coordinate these self-reports with our own observations of how they implement a new environmental science curriculum. More specifically, we compare the teachers' beliefs about learning, goals for the classroom community and for instruction, and their knowledge of science content, and pedagogy. Furthermore, we discuss teaching dilemmas, which arise for these teachers as their identities and practices intersect and at times conflict. We argue, however, that a focus on practice and outcomes is an important, but limited aspect of what we, as a field, need to consider when attempting to understand the complexities of teaching and learning. Therefore, we continue to expand our understanding of two science classrooms as we examine the teachers' multiple identities in relation to their implementation of a science curriculum. The identity portraits from this study provide a rich and complicated account of the implementation of a science curriculum and illuminate a number of potential obstacles and pitfalls, which may inform the way we as a field reflect on curriculum and professional development.