Children all around the world pass through a number of transitions in educational systems. These transitions are organised in different ways in different countries. In Sweden, children pass through three school forms in early childhood education: preschool, preschool class and primary school. In a research project funded by the Swedish Research Council, the Swedish POET group conducted case studies in three municipalities, using participant observations, semi-structured interviews and focus group interviews. The aim has been to deepen the understanding of children’s learning journeys from preschool into school. A second aim has been to examine the long-term implications of educational practices across the transitions for children’s learning and participation. In this chapter, some findings from the research project are presented. The results show how the complex structure of Swedish early childhood education creates challenges for children and their learning journeys.