This chapter has a strong emphasis on promoting mental health and emotional well-being. It also recognizes that people with intellectual disabilities may develop mental health problems similar to, but perhaps more frequently than, people who do not have intellectual disabilities. This chapter considers what emotional well-being is, factors contributing to mental health, and the importance of assertiveness. It then explores how to support people with intellectual disabilities to access general primary, secondary, and tertiary mental health services, before giving specific consideration to anxiety, psychotic and organic disorders, dementia, psychopathology, autistic spectrum disorders, self-harm, substance misuse, and the challenges to emotional well-being that may arise from the experience of bereavement.