This qualitative study examines obstacles hindering social inclusion into mainstream classes from the perspective of Czech high school students with congenital physical disabilities. Data obtained from in-depth interviews were subjected to a situational analysis, with results indicating that the participants (N=10) perceived as challenging their social inclusion into mainstream classes, which took place in four phases. The study participants reported three elements which can be seen as barriers to their social inclusion: (1) their classmates' lack of information regarding special educational needs, even not being informed that a such a student would be joining the class; (2) the presence of an assistant in the classroom; and (3) the lack of out-of-school interactions of the participants with their classmates. To avoid these challenges and to facilitate the social inclusion of students with disabilities into the class, it is recommended to concentrate on anticipative psychosocial class preparation as well as on strengthening social interactions based on cooperative learning and disability awareness techniques.