Closure of institutions designed for adults with intellectual disability (ID) has meant that those with more complex psychiatric and/or medical conditions have been admitted to health care settings designed for the general population of non-disabled adults. This paper describes the characteristics and service utilization of all persons with ID receiving care in Ontario's complex continuing care hospitals, and compares them to patients without ID in the same setting. Overall, patients with ID appeared to be more clinically complex given their higher rates of functional impairment and aggressive behaviour, despite exhibiting less medical complexity. However, interventions mostly focused on behaviour management.