The plight of people with learning disabilities who have mental health problems has become an issue of contemporary importance in the provision of health services to this section of the population. This paper will argue that learning disability nursing has a central role to play in the promotion of mental health for this client group ( Department of Health 1995a). However, learning disability nursing presently operates without a clear model of mental health. Therefore, before this potential can be realized there is a need to establish the common ground between the discourses of learning disability nursing and those of psychiatric nursing which might be related to this client group. This paper begins by identifying the background issues relating to the problems of meeting the mental health needs of people with learning disabilities. It then proposes that an applied behavioural approach has the potential to provide a coherent theory that can link the discourses of normalization, developmental psychiatry and mental health nursing, whilst also establishing the applied behavioural approach as a powerful technology upon which meaningful interventions can be designed.