Background An evaluation report of the mathematics initiative in Sweden points out certain aspects for succeeding in using Learning Study as a method for developing mathematics education. These aspects are (1) a limited content, (2) qualified tutoring, (3) set-aside time and (4) supportive school leaders. Purpose Our purpose is to share our experiences from tutoring different municipality Learning Study projects, by highlighting aspects that could be regarded as crucial for a successful project. Design In order to get better results in students' achievements in mathematics, the teachers attended a municipality Learning Study project, aimed to develop mathematics teaching, especially with focus on content. The first project started in 2010 and the last ongoing project will be finished in spring 2013. Totally approx. 70 mathematics teachers (grade 1-9) together with tutors and project managers were involved. Main activities have been lectures and group discussions of books and articles about Learning Study together with planning, developing and carrying through lessons according to the Learning Study model. Overall, a total amount of about 40 LearningStudies will be fulfilled before summer 2013. Findings As tutors  in the projects we have experienced some aspects that we, from our point of view, believe could affect and be crucial for the outcome of Learning Study projects. We present our findings divided into three main themes (1) General aspects, e.g. visible project management, distinct organization and a compressed Learning Study cycle, (2) Successful groups, e. g. profound understanding of fundamental mathematics, knowledge and awareness about curriculum, and high expectations on students’ achievements. Finally, a third theme has emerged, through analyzing videotaped lessons, tests and materials from project evaluations, (3) Impact on teaching. Some examples are (a) increased and conscious use of manipulatives, (b) increased use of group discussions, and (c) less time for students’ individual work in textbooks.