Background: Many national and regional clinical guidelines emphasise the need for good communication of information to young people and their parent/carers about what to expect during transition into adult services. Recent research indicates only a minority of young people in need of transition for Attention Deficit Hyperactivity Disorder (ADHD) experience continuity of care into adulthood, with additional concerns about quality of transition. This qualitative study explored the role that information plays in experiences of transition from the perspectives of parent/carers and young people. Methods: Participants were recruited from 10 National Health Service Trusts, located across England, with varying service configurations. Ninety two qualitative interviews were conducted: 64 with young people with ADHD at different stages relative to transition, and 28 with parent/carers. Thematic analysis of data was completed using the Framework Method. Results: Interviewees reported a range of experiences; however reliance on parent/carers to gather and translate key information, and negative experiences associated with poor communication of information, were universal. Three themes emerged: Navigating information with help from parents; Information on ADHD into adulthood; Information about the transition process. The first revealed the essential role of parent in the translation and application of information, the other two explored distinct types of information necessary for a smooth transition. Interviewees made recommendations for clinical practice similar to UK (United Kingdom) National Institute for Health and Care Excellence (NICE) guidelines, with an additional emphasis on providing nuanced information on ADHD as a potentially long term condition. It was important to interviewees that General Practitioners had a basic understanding of adult ADHD and also had access to information about service provision. Conclusions: Our findings illustrate that the availability and communication of information to young people and their parent/carers is an essential component of the transition process between child and adult ADHD services. How and when it is provided may support or impede transition. This study constitutes a substantial contribution to the evidence base, drawing on interviews from a range of participants across England and from Trusts offering different types of services.