Using the case of the Flemish policy on educational quality and based on a series of case studies, the author argues that the impact of central policy measures on educational practices in schools is never simply straightforward. Policy measures are always interpreted by and translated to the particular context of a school. In these processes of interpretation the teachers' and principal's agenda of professional interests plays a crucial role. Taking up the micropolitical perspective on schools as a descriptive and analytical theoretical lens, the author argues that these interests reflect different types of working conditions that are considered valuable or necessary by the teachers and principal to do a good job. If these conditions are absent, threatened or lost, people will engage in micropolitical actions in order to establish, safeguard or restore the desirable working conditions. Five different categories of professional interests were identified in the analysis of the case study data. Describing these categories, the author shows how the macropolitical agenda gets caught up in the micropolitics of the local schools during the policy implementation.