This article examines how epistemological differences regarding knowledge production and material differences in the conditions of teaching influence teachers' and teacher educators' understandings of learner-centered pedagogy. Emerging from a 5-year collaboration between teams of US and Tanzanian teacher educators, the research focuses on six Tanzanian secondary schools whose teachers participated in a workshop on learner-centered pedagogy and pedagogical content knowledge. We find that teachers' views of knowledge production are profoundly shaped by the cultural, economic, and social contexts in which they teach. We conclude not only that teachers' working conditions are important contextual factors in comparative studies of schooling but that the conditions themselves need to be conceptualized more fully in theories of knowledge production and global/local reforms of teacher education. (Contains 1 table and 10 footnotes.)