Background: There is a dearth of research on the perspectives of adolescent siblings growing up with a brother or sister with an autism spectrum disorder (ASD). Method: Semistructured interviews were used to elicit the perceptions and experiences of 12 typically developing adolescents with a brother with an ASD. Interpretative phenomenological analysis was used. Results: The data analysis of the siblings' perceptions yielded 6 themes: (a) difficulties and negative impact of their brother's condition on themselves and their family, (b) how others' reactions to their brother negatively affected them as siblings, (c) how their histories with their brothers contextualised their present circumstances, (d) the varying degrees of acceptance and tolerance towards their brothers, (e) positive perceptions and experiences with their brothers, and (f) their thoughts and worries about the future. Conclusions: The main implications are for supports to adolescent siblings by helping them to develop skills in managing others' reactions and openly discussing concerns about their brother's future.