The purpose of this study is to test empirically whether and how classroom and school factors contribute to student mathematics learning gains in the border region of North West province, South Africa and Southeastern Botswana. Our results suggest that in both regions, improving teaching quality has an important impact on how much mathematics students learn during the year. The amount of effort put into covering the curriculum and teacher mathematics knowledge are also important factors in the learning gains students make in grade 6 classrooms in southern Africa.