Writing is one of the key competences defined by a number of international bodies as being crucial for students’ learning and work life qualification. The three Scandinavian countries share a common goal of providing equal education for all and have a history of prioritizing extended essay writing as an assessment format in many subjects. The purpose of this article is to investigate writing in the content areas in Scandinavia by focusing on the connection between macro-level decisions and what actually happens in schools and classrooms. We first look at recent curriculum plans in the three countries and show how they have chosen different ways of encouraging or mandating writing in the disciplines. Three case studies, each based on research projects, exemplify what goes on at the meso/micro level: professionalization of science teachers in using writing in Sweden; student perspectives on the challenges and learning potential in mandated written research projects in Danish secondary and upper secondary schools; and teacher-initiated collaboration across content areas in Norway in order to develop better writing practices. We find that although the Scandinavian tradition of extended writing provides favorable conditions for writing in the content areas, there are problems which must be overcome before a successful integration can be expected. One such hindrance is the association of key competences with basic, instrumental skills, while another is the fact that the idea of writing in the content areas has been introduced top-down. Our conclusion is that a combination of macro-, meso-, and micro-level initiatives (top-down and bottom-up) is needed.