Culturally responsive science teaching is using knowledge about the culture and life experiences of students to structure learning that is conducive to their needs. Understanding what teachers need to prepare them to be culturally responsive is a matter of continuous debate. As the focus of multicultural education ventures farther away from its roots, advocating the civil rights of historically oppressed groups, concerns about the gravity of racial inequity on schooling continues. How will this shift in focus influence teachers' capacity to accommodate students' needs resulting from racial inequities in this society, particularly African American students? What knowledge is essential to their effectiveness? This qualitative study examined the instructional practices of two effective middle school science teachers deemed culturally responsive by their administrator on the basis of classroom observations, students' responses and standardized assessment results. Both teachers' classrooms consisted primarily of African American students. Grounded theory was used to analyze the teachers' beliefs and practices in order to identify existing commonalties. Critical race theory was used to identify whether there was any influence of the students' racial identities on the teachers' beliefs and practices. The analysis reveals that the teachers' beliefs and practices were informed by their critical awareness of social constraints imposed upon their African American students' identities. These findings communicate the significance of sociocultural awareness to informing the teachers' instruction, as well as their strategies for managing the varying dynamics occurring in their classrooms. It can be deduced from the findings that an understanding of racial inequities is crucial to the development of sociocultural awareness, and is the foundation for the culturally responsive dispositions and practices of these middle school science teachers.