Background: The present authors examined changes made in disability service organizations supporting residents with intellectual disabilities and challenging behaviours, because these changes may influence residents' support and subsequently their challenging behaviours. Method: In this multiple case study, the present authors collected and qualitatively analysed data (organizational documents, meetings records and focus group reports) on organizational changes made in two specialized Dutch disability service organizations, using ecological theory as a sensitizing framework and the constant comparative method. Results: Themes describing organizational changes in this context were as follows: a messy start to the transition; staff, professionals and managers remain at a distance; staff members' ability to change; clear boundaries between formal and informal caregivers; and staff's feelings of being unheard. Conclusions: Organizational changes can enhance, but also limit, the quality of residential support services provided to people with intellectual disabilities and challenging behaviours. The change process and impact of organizational changes on residents must be examined closely.