The transition from preschool to primary school is an interdisciplinary topic. From a pedagogical point of view, supporting children and families in their transition processes is of interest. Developmental psychological knowledge of central precursor skills provides information on which skills are relevant for a successful transition and which should be promoted accordingly. Physicians who accompany the enrolment examination also contribute their perspective to the transition process. In addition to a theoretical embedding of the transition, this paper therefore focuses on the importance of cooperation between preschool, primary school and families as well as important precursor skills for the transition.