MS-related dementia is an under-recognised and misunderstood aspect of MS. It is relatively rare, occurring in approximately 10% of people with MS, while cognitive impairment in general occurs in 43% or more of people with MS. MS-related dementia is hard to detect on the basis of short social interactions or clinical interviews alone. There are very few clinically relevant scientific articles on this topic to help guide the management and support of people with MS-related dementia. This article was written in a preliminary attempt to address this problem: to describe the clinical presentation and characteristics of MS-related dementia, to alert health professionals to the sensitivities surrounding the use of dementia terminology within the MS community, and to outline the limited nature of the information, advice and support resources currently available in Australia for these middle-aged people with dementia.