In this chapter issues from a study about teachers’ perceptions of children’s diversity in different educational settings are discussed. The chapter also focuses on how these issues can be understood from an ecological point of view. The theoretical framework, used in the referred study, was influenced by an ecological approach to understand children's capabilities in relation to transitions and the learning process. The empirical data originates from focused thema interviews with 36 teacher from preschool, preschool class and first grade in primary school. The result shows that teachers’ perceptions of children´s different capabilites and experiences were influenced by factors from micro to macro level and emphasised the complexity of a dynamic process. Obstacles regarding children's learning and development changed from preschool to first grade in primary school. Teachers' perceptions of diversity involve both ideas of including and also excluding processes, besides dimensions linked to identity and social relations but also changes related to different educational settings. What teachers perceive as "problems", challenges and implications for measures in different educational settings can be of valuable knowledge for all professionals who are interested in children's learning journeys from preschool to school.