Background: Inpatient beds for the psychiatric assessment and treatment of young people (under the age of 18 years) with intellectual disability have become scarce although there is pressure to redevelop them. In the UK, 63% of the NHS beds are at Prudhoe Hospital. This study examines their role and utility in relation to community services, both local and national. Method: A case note study of the 96 young people admitted over three years was supplemented by a standardised interview canvassing the opinion of the staff involved, both within the units and in the community. Results: Two groups emerged: those with more severe disability who were admitted for neuropsychiatric management (63%) and those, predominantly adolescent, whose problems were closer to mainstream psychiatry but whose intellectual disability prevented their needs being met adequately by mainstream services (37%). Admissions were equally divided between those from the immediate vicinity and nationally. For 43% the primary aim was to disentangle the extent of the environmental effect on the individual: the remainder were admitted for various reasons including, for example, the need to protect the individual from harming themselves or others, unusually complex or hazardous treatment or the carers inability to cope with the treatment plan. All admissions were thought appropriate but, had the community resources been better, 18% were avoidable. Conclusions: Admission is necessary for a small number of young people who are not readily managed within mainstream units. While the number may be reduced by better community provision, this is likely to partially offset by better case finding. Inpatient facilities should be closely linked with community services; a point reinforced by the prolongation of admissions because a shortfall in community resources.