It has been suggested in the literature on family caregiving for persons with Alzheimer's dementia (AD) that levels of objective and subjective burden among carers often predict institutionalization of the persons with AD. There is a paucity of measures to assess whether perceived burden among formal caregivers may also predict movement to more restrictive settings for persons with intellectual disabilities (ID) and AD. This study focused upon the development of a measure of subjective burden, The Caregiving Difficulty Scale Intellectual Disability (CDS-ID) as a first step in addressing this measurement deficit. An existing caregiver subjective burden scale, the Caregiving Hassles Scale (CHS) was adapted for use with 203 staff caregivers of persons with ID and AD. Preliminary testing of existing CHS items and proposed new items was carried out in two countries, Ireland and the USA. Confirmatory factor analysis with the existing items and exploratory factor analysis with existing and proposed new items for the scale was used to establish the content and test the psychometric properties of a revised scale, the CDS-ID. On the existing CHS items, staff carers appeared to experience greater subjective burden than has been reported for family caregivers. However, the psychometric properties of the CHS found with this population were poor. Factor analysis produced a revised scale, the CDS-ID with three subscales with Cronbach alphas ranging from 0.75 to 0.93 and 38 items overall. This new scale when used with objective burden and other scales offers an opportunity to more systematically measure the difficulties staff experience when caring for persons with ID who present with symptoms of AD.