This study aimed to investigate the impact of external factors on the experiences and family relationships of autistic adolescents and their families. A qualitative approach was used, with in-depth interviews conducted with 30 participants, including autistic adolescents, siblings and parents from within families with an autistic adolescent family member. The findings suggest that external factors significantly influence the well-being of autistic adolescents and their families. The school environment was identified as a significant factor, with sensory overload, bullying and adverse interactions with teachers having a negative impact on the mental health and quality of family relationships for participants. In addition, the study highlighted that isolation and stigma were major concerns for families, suggesting a need for public efforts to raise awareness and understanding of autism. The lack of appropriate support and services was also identified as a significant challenge that families face. The study highlights the need for person-centred approaches to service provision, which involves including autistic adolescents and their families in the design and delivery of support and services. The study recommends collaboration among schools, service providers, and families, as well as efforts to promote autism-friendly environments in schools and the broader community. Lay abstract The influence of the environment on different groups of people with disabilities has rarely been studied in the context of neurodevelopmental disabilities, such as autism, in adolescence. This study explored how external responses to autism affect the experiences, outcomes and family relationships of autistic adolescents and their family members, including siblings and parents. This study adds to the knowledge of factors that contribute to the social disadvantage and exclusion autistic adolescents and their families face in their communities. Interviews with 30 participants from families with an autistic adolescent show that external factors greatly impact the well-being of autistic adolescents and their families. The school environment, including sensory overload, bullying and negative interactions with teachers, was found to be a key factor that negatively influenced mental health and family relationships. The study also revealed that isolation and stigma are major concerns for families, indicating the importance of public awareness campaigns to increase understanding of autism. In addition, the lack of adequate support and services presented significant challenges for families. The study emphasises the importance of person-centred approaches to providing services, which involve including autistic individuals and their families in designing and delivering support.