BACKGROUND: Although childhood hyperactivity is a common, serious, and treatable disorder, most affected children in Britain do not receive effective treatment. AIM: To investigate the views that parents and GPs hold about hyperactivity, and to explore how far these views, and clashes between these views, influence access to services. METHOD: Qualitative study making use of semi-structured interviews with 10 general practitioners (GPs) and 29 parents of hyperactive children drawn from parents' groups, community services, and specialist clinics. RESULTS: The views of parents and GPs differed markedly. Parents generally saw severe hyperactivity as a long-lasting, biologically-based problem that needed treatment in its own right and that benefited from diagnosis. Most of the GPs were unsure whether hyperactivity was a medical disorder warranting a label and specific treatment, and often saw it as a passing phase related to family stresses. Parents worried that professionals would blame them for their child's problem, whereas many GPs saw the parent's tendency to medicalise as a way to avoid thinking about their own shortcomings in parenting. CONCLUSION: Access to treatment was influenced by the views of parents and GPs, by the clashes between these views, and by each group's perceptions of the other group's beliefs. Clashes between the views of parents and GPs were particularly likely to lead to misunderstandings, dissatisfaction, and lack of access to effective help.