Autistic people diagnosed in adulthood often report that the experience can be life-changing, but there are issues with the diagnostic pathway. Few studies consider the views of people currently seeking diagnosis or contextualise the experience of diagnosis around developing an autistic identity. In this qualitative participatory study, we explored experiences of navigating an autism diagnosis in adulthood in the UK. We recruited six women (aged 21–46 years) who were seeking diagnosis, who worked with the academic researchers across four sessions to develop the study, share their experiences and analyse the themes. In one session, they completed a semi-structured interview alongside photovoice, a community-based action method, to explain and reflect on their experiences. We used reflexive thematic analysis to identify patterns, with four key themes identified: (1) ‘everything shattered’, (2) ‘being seen’, (3) ‘understanding not judgement, please’ and (4) ‘here’s a leaflet, off you go’. The themes reflected a desire for change and improved support for both diagnosis and developing autistic identity. Following photovoice methodology, together we identified actions to improve adult diagnosis, including involving autistic people in making improvements to the diagnostic criteria, for key professional and community groups to listen more to autistic people and for diagnostic support services to be flexible and appreciative of wider neurodivergence and intersectionality. Lay abstract Lots of people seek an autism diagnosis as an adult, and they often say that being diagnosed can be positively life-changing, but the experience of getting a diagnosis can be difficult. We often do not hear the views of people currently looking for a diagnosis, or talk to them about how diagnosis relates to their identity. In our study, we looked at experiences of people currently seeking an autism diagnosis in the UK. We used participatory methods, where six people seeking diagnosis were included as collaborators in the research. They took part in four different sessions, where they helped to shape the research, took part in interviews about their experiences and helped to analyse the patterns in all the interviews. We also used something called photovoice during the interviews, where they could use photos to show how they felt about navigating a diagnosis. We identified four common themes: (1) everyone had experienced some form of crisis before seeking diagnosis; (2) when they realised they were autistic, they felt seen; (3) the diagnostic process and criteria were not working, and they felt judged by clinicians and (4) there was limited support available after diagnosis. In another session, we identified actions that need to be taken which have implications for policy and practice, including improving the diagnostic process and criteria with autistic people, autistic people being listened to more by people like general practitioners and clinicians and diagnosis services needing to be more flexible and appreciate different aspects of someone’s identity and neurodivergence.