Background: Government guidelines promote the use of mainstream mental health services for people with intellectual disabilities whenever possible. However, little is known about the experiences of people with intellectual disabilities who use such services. Materials and Methods: Face-to-face interviews with service users, carers and community nurses were completed and analysed on a case by case basis using interpretative phenomenological analysis. The results were followed up in focus groups with service providers. Results: Positive aspects included the provision of respite, particularly for carers, and good basic care. These were outweighed by a perception of the admission as disempowering and lacking in flexible treatment provision. Accessing help emerged as a major problem, as well as the prospect of staff neglecting the specific needs of people with intellectual disabilities. Conclusions: While there were some indications of improvements in line with recent policies and guidance, mainstream services seem a long way off realizing aims of easy accessibility, person-centred practices and active partnership with intellectual disability services.