Background and purpose: Many researchers agree that teachers' learning processes are social and that teachers need to be brought together to learn from each other. Researchers have also stated that intellectual and pedagogical change requires professional development activities that take place over a period of time in school. The purpose of the study presented in the article was to develop knowledge about the teachers' learning when taking part in a school-based development project. Main argument: The study shows that it takes some time before the teachers identify with the work in school-based development. Even though the national authorities decided what to focus on during the development work, the participating teachers felt that they had autonomy in the work. The study presented in the article shows that it is important for the teachers' learning culture that they are listened to and taken into consideration and that the leaders have competence in leading school-based development to support the teachers' learning. Sources of evidence and method: The article is based on a study connected with school-based development in three lower secondary schools. Qualitative interviews were used as the data-collection strategy to capture the teachers' and school leaders' experiences and reflections. Conclusion: The article presents new knowledge connected with teachers' learning in school-based development. The study presented in the article shows that schools' learning culture can make a difference for the teachers' learning and their job satisfaction and wellbeing.