There is a general lack of self-report data from service users with an intellectual disability (ID) about their views of psychological interventions. This research explored the views and experiences of female inpatients, with a diagnosis of a personality disorder and an ID, about dialectical behaviour therapy (DBT). Semi-structured interviews were used with 10 women, recruited from two independent mental health hospitals. The interviews were analysed using interpretative phenomenological analysis. Participants showed varying levels of understanding of DBT. Findings highlight the need for a standardized approach with a suitably adapted structure and curriculum to meet the needs of inpatients with an ID. Factors such as the therapeutic relationship were identified as playing a role in participants’ motivation, engagement and participation in DBT.