The growing interest in the use of cognitive behaviour therapy with children and young people has been encouraged by emerging evidence suggesting that CBT is effective with a wide range of child disorders. Typically, models and techniques developed for work with adults have been extended downwards and applied to children. This review questions the appropriateness of this approach and selectively identifies a number of key issues that need to be addressed. The absence of developmentally appropriate theoretical models to understand the onset and maintenance of maladaptive cognitive processes in children is highlighted. This lack of a coherent theoretical framework has led to a proliferation of diverse interventions falling under the general umbrella of cognitive behaviour therapy with the predominant emphasis being behavioural, rather than cognitive. Developmental factors, the nature, extent and type of cognitive processes in children and the important role of the parent in the onset and treatment of childhood problems have received comparatively little attention. There is a need to understand more about the cognitive processes of children and young people and to develop robust and testable developmentally appropriate theoretical models. In turn this will begin to address the question of which specific cognitive behaviour therapy programmes are effective for which childhood problems.