This presentation aims at exploring how notions about STEM (Science, Technology, Engineering,Mathematics) in different contexts, times, scales and places might affect STEM-practices inpreschool/ECE (Early Childhood Education) as well as preschool teacher education/ECTE (EarlyChildhood Teacher Education). For many years, studies have highlighted the urge to deal with genderednotions related to STEM within school and higher education. Latest years, researchers have also startedto point at preschool/ECE as a decisive arena when it comes to counteracting and reshaping genderednotions related to STEM (e.g. Campbell et al., 2020; Fleer 2021). While some (e.g. Hachey, 2020) statethat the work with fixing ‘the leaking STEM-pipeline’ (dropout in STEM education) must start inpreschool/ECE, I argue that it must start in ECTE.To explore the aim, the presentation is built on diffractive readings of agential cuts (Barad, 2014) madefrom the STEM area. The concept of agential cuts come from Barad’s theory of Agential realism anddiffractive methodology (Barad 2014). An agential cut can be a part or detail that is ‘cut out’ from theworld’s multiplicity, described by Barad as ‘cutting-together-apart’. The agential cuts for this presentation was made from conceptual and empirical research papers, apopular scientific book, reports, surveys and statistics, as well as a field study in preschool practice. The purpose with these agential cuts was to read them ‘through one another’ to look for what insights oraspects that could emerge within the ‘phenomenon of STEM in ECE as well as STEM in ECTE’ that arenot apparent in the same way as one confronts each agential cut separately. The findings show that knowledge about gendered notions related to STEM, as well as explorations ofalternative ways to know and act in relation to STEM, are as urgent to ECTE students as subject-specificknowledge (e.g. Gullberg et al., 2012). Even students that enter ECTE with positive feelings towardsSTEM can carry narrow views of what STEM is, which if not getting challenged, might be brought intotheir future STEM-teaching, risking to cause microaggressions towards children. This makes feministperspectives that encourages explorations and problematizations of what the STEM-subjects can be,how they can be done, with what and by whom, an important aspect within ECTE. At first, feministperspectives and a feminist pedagogy might seem especially crucial in relation to girls, so that futurepreschool/ECE teachers develop ways to not (unconsciously) interpret girls’ doings as ‘less STEM’.However, the diffractive readings show that this is of importance for all children. The findings includeexamples of how notions of what STEM is and is not, risk to affect all children’s STEM-learning andidentity formation in narrowing ways, irrespective of their gender. The presentation has relevance to Nordic educational research since gender norms affect both STEMeducation and the labour market also within the Nordic countries (e.g. Hussénius, 2020) and must assuch be dealt with from ECTE, ECE and beyond also in the Nordic context.