A significant proportion of people with Down syndrome will develop Alzheimer’s disease, but their impaired cognitive abilities and healthcare professionals’ lack of knowledge about how Alzheimer’s disease presents in people with Down syndrome may lead to the condition going undetected or being misdiagnosed. This article defines Down syndrome and Alzheimer’s disease, and describes the correlation between the two. The assessment methods for Alzheimer’s disease will be discussed, along with the many challenges associated with evaluating people with Down syndrome. This article highlights the need for learning disability nurses to be fully informed about the condition and explains assessment challenges.