This paper is based on an exploration of the ways in which primary science student teachers recognizeand learn about issues that shape their own professional learning. The paper discusses differentperspectives of “knowledgebase needed for teaching” and Shulman’s concept of pedagogical contentknowledge, and explores how elements of knowledge are to be recognized and further developedwithin primary teacher education. Primary science student teacher participants (n = 25) were stimulatedto use portfolios as a tool to reflect upon situations within their six weeks teaching practice inpre- and primary schools in order to facilitate recognizing their knowledge needs. The results give aninsight into what situations within the teaching practice that student teachers consider as importantfor their own learning to teach primary maths and science