Facilitating the learning and participation of pupils with Asperger syndrome and high-functioning autism (herein referred to as AS) in mainstream schools is complex and poorly understood. We report on a small-scale qualitative study of the views and experiences of 20 such pupils drawn from four secondary schools in north-west England. Data were collected through semi-structured interviews and pupil diaries. Interpretive phenomenological analysis was used to explore how pupils with AS make sense of their educational experiences. The central theme was how participants constructed their understanding of what their AS meant to them. This was often characterized by negative perceptions of their differences, such as being 'retarded' or having a 'bad brain'. The links between this understanding and reported difficulties with peers and teachers, the desire to 'fit in', and other themes are discussed. The implications of these findings for policy and practice in this area are also presented.