This article focuses on presenting success factors for a group of teach-ers in carrying out a learning study in mathematics at their school.The research questions are: what are the actions of the school teach-ing community during development projects? What factors enablea group of teachers to carry out a learning study at their school?Activity theory provides a holistic framework to investigate rela-tionships among the components present in a learning study. Theresults are based on analysis of interviews with teachers, students,principal organizers of schools and project coordinators, videotapedlessons, students’tests and minutes taken at meetings of mathemat-ics projects. The results show that the skills of facilitators, the timedevoted to collaborative work, the link to learning theory and avoid-ing overly comprehensive content when teaching lessons are impor-tant promoting factors in mathematics teaching. The findings raiseimportant questions about the way in which teacher work within uni-versities.