In this contribution, the author will first discuss the concept of 'transnational education spaces' and point out some of the challenges for school development implied in this perspective on education. In the second part, he will present the ongoing research project "Multilingualism as a field of action in intercultural school development. An intervention study in primary school" (MIKS-Projekt). In his outlook, he will delineate first field experiences in the context of the MIKS-project. The experiences demonstrate that school development, which takes into consideration migration-related multilingualism as a result of transnational processes, is still a project for the future in German schools because many schools have not even identified a need for this particular kind of development. (DIPF/Orig.).