This article reports findings from a research and professional development project at two high schools located in low-income, urban communities of color. The project collaborates with teachers on improving their instructional practices, using a framework of culturally relevant mathematics pedagogy, which is described in detail here. We present results from a qualitative and quantitative analysis of mathematics instruction in 68 classroom observations of seven teachers. In particular, we use culturally relevant mathematics pedagogy as a lens through which to analyze instruction and the associated opportunities to learn mathematics provided to students.