We studied the implementation and associated factors of strategies (e.g. sports after school and during lunch break, active schoolyards, active school commuting) and organizational principles (e.g. safe bike racks, pupil involvement) that facilitate the physical activity (PA)-promoting role of schools. Key representatives of 111 elementary and 125 secondary schools filled out an online survey. Less than half of the elementary schools organized sports during lunch-break or after school. In secondary schools the least implemented strategies were the promotion of active school commuting and after-school sports. In general pupil, parental and community involvement scored low. Better knowledge of community schools and having attended in-service training were associated with higher implementation scores in elementary and secondary schools. Better implementation of the strategies was found in larger schools. Participation in activities from the School Sports Association and more perceived interest from parents and the school board were also associated with higher implementation scores. In conclusion, knowledge of community schools and in-service training next to sufficient human resources are potential key factors to promote PA. Efforts are needed to convince and help schools to increase parental and pupil involvement and to build a policy on school-community partnerships.