This article explores how comprehensive school teachers' sense of professional agency changes in the context of large-scale national educational change in Finland. We analysed the premises on which teachers (n = 100) view themselves and their work in terms of developing their own school, catalysed by the large-scale national change. The study included theory-driven interventions in the case school communities, as well as pre- and post-test measurements. The results suggested that the learning of active professional agency was facilitated among teachers during the 2 years of development work. A significant number of teachers had adopted a more holistic orientation towards the reform. Moreover, the number of teachers who considered themselves as the subjects of the development work increased slightly. This increase suggests that teachers' intentional and responsible management of new learning proceeds from the interpersonal meaning-making process to the internal process that regulates the elements of a teacher's professional agency.