In the past decades an impressive number of publications on inclusion have been written, not always with ‘inclusion’ as the central concept, but also using concepts like ‘mainstreaming’ or ‘integration’. These publications address a wide variety of subjects: the philosophy behind inclusion, the necessary requirements for inclusion, the effects on inclusion for pupils, parents, schools and teachers, etc. In most of these publications one or more factors considered relevant for realizing an inclusive school are put forward, for instance: a much more differentiated curriculum, teacher support teams, legislation and regulations supporting inclusion. Studies show that minor adaptations in the regular curriculum can easily lead to would-be inclusion, that a teacher support team and intensive staff development make teachers more self-confident and willing to accept a special needs pupil, and that new legislation affects the referral behaviour of schools.