As a teacher educator, feedback from students is important to ensure there is time for my own reflection to inform and develop my practice and curriculum design within formal expectations of initial teacher education. This paper considers the perceptions and expectations of a sample of student teachers, situated in a Higher Education Institution (HEI) in the UK, of teaching primary science and the perceived subject knowledge required. The recommendations from this paper highlight the importance of ensuring that teacher educators support the development of competent practitioners to address concerns about subject knowledge and developing confidence in teaching primary science. The findings concur with previous research into how best to support low confidence of student teachers to teach science, support the perception of the importance of what you know and what you need to know to teach, as well as a need for fixed ideas even in pedagogical knowledge. As I was able to identify similar themes from student feedback as highlighted in my review of the literature, this adds support to those studies. This paper recommends that we explore and raise awareness of pre service teachers' conceptions about what it means to teach primary science, to be more explicit about looking at and signposting the different types of knowledge involved in teaching and to consider how renaming the science subject knowledge sessions can eliminate misconceptions about their purpose.