<p>Lack of science content knowledge has often been suggested as underpinning primary teachers' reluctance to teach science or to provide limited learning opportunities when doing so. Understanding better the full range and nature of teacher knowledges that afford useful science learning opportunities in primary science education could produce a more positive view of primary teachers' potential for science teaching and usefully inform professional development in science. This research used a multiple case study approach to identify the nature of knowledges and beliefs that three teachers from schools well regarded for teaching science at Years 7 and 8 brought to their implementation of a unit of work in science. Students' perceptions of learning pertaining to the science unit were also examined. The influence of teacher knowledges on opportunities for science learning was considered and the ways in which the teachers developed science related teacher knowledges was investigated. Sociocultural theories of learning underpin this study and the extent to which the teachers incorporated sociocultural approaches in their science teaching was a particular focus. Frameworks guiding the analysis of the range of teacher knowledges and of sociocultural teaching approaches were developed from the literature. Data for each case study included observations and transcripts of recordings of the lessons forming each science unit together with multiple interviews with the teacher throughout its implementation. Interviews with focus students during and following the unit along with responses to a questionnaire completed by the class at the end of the unit provided insights into students’ perceptions of what they had learned. This study found that the teachers drew on a wide range of knowledges and beliefs to promote science learning. The teachers employing sociocultural approaches afforded most syntactic science learning opportunities. Crucially influential on the nature of science learning that was promoted was the teacher's orientation to science teaching, in particular, beliefs about the purposes and nature of science and science teaching. Four processes were identified that facilitated the teachers' development of science and pedagogical content knowledge: intentional development, reflection, repetition, and engaging and observing students in investigating the natural world. The nature of knowledge developed by each teacher was afforded and constrained by their orientation to science teaching and their recognition of and access to, sources of support. Learning science content, i.e., substantive science learning, was identified by students where this had been the focus of learning and assessment opportunities because of their teacher's particular orientation. Learning about the nature of science, i.e., syntactic science learning, was identified where this was the sole focus of learning and assessment opportunities. In the one case where the teacher's orientation afforded both types of learning opportunity with apparently equal emphasis, students more readily identified substantive science ideas over syntactic ideas as new or important learning.</p>