In this research, a case study, we adopted ethnography as logic of inquiry to learn about teaching for diverse groups in middle school science classrooms. Multiple data sources were used: participant observation, video and audio records, field notes and semi-structured interviews. We analyzed interviews with two teachers, as well as classroom episodes to construct, through contrast, a characterization of two types of practice involving diversity in the classroom. The first teacher show concerns with introducing students in school culture. She tried to “translate” terms that students do not understand, explaining their meanings. In this process, teaching subject matter knowledge (SMK) is a secondary goal. The other teacher emphasized SMK, trying to establish connections between science content and students’ everyday life experiences. Both teachers do not acknowledge significant influences in science learning related to gender, social class, and ethnicity.