Moving between schools is a common experience for autistic students. Despite this, only one study has explored factors which lead to mainstream school mobility for autistic students, and this was for those students with low support needs. The aim of this study was to understand parents’ experiences and decisions around moving their autistic child between mainstream schools. A qualitative method was used to conduct semi-structured interviews with 19 parents whose child had a diagnosis of autism at Level 2. Data were analysed using thematic analysis and four themes were generated: Realising a disconnect, Feeling marginalised by the school system, Deciding to stay or leave, and After the move. Each parent’s story and final decisions were highly individual, but mostly underpinned by a perception of inadequate support for the child and parent feelings of disempowerment. The decisions parents made about moving schools for their child were not straightforward, but the final choice to stay or leave was in the interests of their child’s education and mental health. The findings highlight the need for schools and education departments to develop a systemic response to issues affecting autistic students and their parents in mainstream settings.