Persons with intellectual disability commonly present to healthcare professionals with behaviours of concern, which have a significant impact on their quality of life, as well as that of their caregivers. These behaviours often result from a combination of complex factors, which includes physical and mental health conditions, psycho-emotional issues, and social-environmental difficulties, all of which are made more challenging by their inherent cognitive and communication difficulties. A comprehensive assessment is essential, and the objective will be to determine the underlying reason(s) for the behaviour. Depending on the underlying cause(s) ascertained, pharmacological and/or non-pharmacological treatment needs to be implemented promptly and appropriately in a person-centred manner. The impact of these behaviours on caregivers cannot be overlooked and they must be supported and engaged actively throughout the process. Regular review and monitoring of the effectiveness as well as adverse effects of the interventions will need to be carried out. This article aims to outline an approach to the assessment and management of these behaviours.