While progress has been made for including students with disability into mainstream schools, trends point to problems for students with Asperger syndrome (AS) diagnosis who have a propensity to dropping out of school. Teachers’ perceptions and understanding of AS will affect expectations and the attainment of educational targets. Thus, to avoid barriers to students’ learning and participation, there is a need to shed light on teachers’ perceptions and beliefs that bear on teachers educational provision for students with AS. The aim of the study was therefore to elucidate mainstream teachers’ representations of students with AS by using the theoretical framework of Social Representation Theory and particularly looking at the effects of the sex of the teacher, grade level being taught and when the teachers received training themselves. Teachers in mainstream schools in Sweden were invited to complete a web-based questionnaire (N = 170). Data were collected through an association task where the participants were asked to produce up to five words or phrases for the stimulus phrase ‘student with Asperger diagnosis’. The data were analysed through categorisation. We found that two-thirds of the macro-categories of mentions relate to ‘disabling aspects’, ‘individual needs’ and ‘individual characteristics’, while a third of the elements were tied to the environment and educational provision. Our results suggest that a medical approach dominates especially earlier trained teachers; however, there is a tendency to view the school environment as increasingly important. Representations about the disabling aspects decreased with the increase in the grades being taught, whereas the educational aspects increase with the increase in grades. Male teachers are more prone to relate to environmental aspects and educational provision while female teachers more often relate to needs and disability. We conclude that teachers tend to view AS from a medical approach but that the school environment is seen as increasingly important.