Strengthening school leadership for the recovery of learning disabilities and aligning the school organization to the needs of students and of the school team is of crucial importance. To that end, the Flemish Minstry of Education sets up professional development initiatives in which the collective learning of school leaders is a key element. This research project aims to map the conditions, processes and effects of these PDI s, in order to make recommendations in view of futire school leadership development and in order to present good practices in school leaders' collective learning.