Finnish society, including the Swedish-medium school, has traditionally been considered linguistically and culturally homogeneous. During the last twenty years there has been a distinct development towards increasingly heterogeneous municipalities and schools, but with great local variations. The aim of his article is to present some teacher perspectives on this development towards linguistically and culturally more heterogeneous primary school classrooms, what kind of new challenges teachers experience and what tools they express the need for. The data consist of qualitative interviews and focus discussions with teachers and headmasters in Swedish-medium classrooms and CLIL classrooms, representing both urban and rural settings. The results show some variation concerning the types of multilingualism evident in different contexts and the views on multilingualism and multiculturalism. A number of challenges and needed tools are identified. These call for a professional, facilitating teacher role, as well as for complex societal networks.