Transition from primary to secondary school has been a focus of concern regarding pupil anxiety, social integration, lack of progression and under-achievement, particularly for children/young people with special educational needs (SEN). Previous studies often over-depended on data from professionals and treated all SEN as similar. This study gathered data specifically from children/young people with autistic spectrum disorders and their parents (contrasting this with the views of professionals), adopting a more intensive case study methodology. A large number of transition support arrangements were identified. In 4/5 cases the arrangements were delayed and/or incomplete, with a number of specific problems. Despite the size and complexity of their new school, the children/young people were positive about transition, but wanted real inclusion in school activities. Parental evaluations of transition arrangements were considerably lower than those of professionals. Stakeholder perceptions of what worked and did not work were contrasted. Commonalities and differences in the relevant development needs of school staff were identified. Implications for future research, policy and practice are explored. (Contains 7 tables.)