This study demonstrates the potential for teacher research to lead to critical inquiry and change in social studies classrooms. It presents four portraits of experienced social studies teachers engaged in critical teacher research. These teachers posed critical questions about the means and purposes of schooling, while engaging their students in more democratic conversations. In the process they referred to critical theory to analyze classroom data and to articulate new understandings. The teacher research cycle seems to have empowered both the teachers and their students. The teachers reported that they were transformed by their teacher research as they developed greater awareness of issues of race and ethnicity and worked as advocates for their marginalized students. As a result of their teacher research, they reportedly pursued more culturally relevant instruction in their classrooms. (Contains 4 notes and 4 tables.)