Background: The objectives of this study were: (i) to compare the behavioural intentions of high school students towards individuals with intellectual disabilities and individuals with physical disabilities and (ii) to explore reasons for these behavioural intentions. Materials and methods: A sample of 319 Grade 9 and Grade 12 students in Ontario, Canada, completed a questionnaire regarding their behavioural intentions towards peers with intellectual or physical disabilities. They also responded to open-ended questions concerning their feelings about participating in a class task or social activity with these individuals. Results: Behavioural intentions towards students with intellectual disabilities were significantly more negative than were those towards students with physical disabilities. This difference was also reflected in responses to the open-ended questions. Common reasons for discomfort were perceived dissimilarities in interests or abilities. Conclusions: Future efforts should aim to help students with and without disabilities find commonalities and to encourage reciprocity in their interactions.