This paper reviews the importance of transition to adult services for young people with ADHD. Different models are described and evidence sought for their effectiveness in clinical practice. Models of care for children with ADHD include specialised mental health services, individual paediatricians and child and adolescent psychiatrists. Although it might be expected that transition would be to equivalent adult teams or specialists, studies have shown that transition may not run smoothly, and the adult services are frequently inadequate. This may result in attrition from treatment or discharge to the general practitioner. Adult mental health services for transitioning young people with ADHD are under-resourced. The way forward may be a generic ADHD specialist or service, treating ADHD across the lifespan and avoiding the need for transition.