This paper explores the different ways that primary school teachers in Uganda navigate the boundary between school science and everyday knowledge in the context of a centrally mandated curriculum innovation. The paper is based on a study of the pedagogic practices of 16 teachers in eight Ugandan primary schools that were selected on the basis of having a track record of either high or low academic achievement in the public primary school-leaving examination. The official primary school curriculum in Uganda prescribes that science be taught in an integrated form, including integration between science subject knowledge and everyday knowledge. The strategies that teachers in the study adopted in relating science to everyday knowledge was a key feature that differentiated between pedagogic practices in the high-performing and low-performing schools. In high-performing schools, teachers recruited everyday knowledge as a resource for learning science as a specialised discourse; whereas in the low-performing schools, acquiring everyday knowledge was viewed as an end in itself. The paper, then, considers the implications of differences in teachers' pedagogic strategies for the kinds of knowledge to which learners are given access.