BACKGROUND: Management of dementia, particularly the use of pharmacological treatments, in the oldest old and those with frailty is complex because of the multiple types of dementia, comorbidities, polypharmacy, and side effects. Current national dementia guidelines lack recommendations for this group. This study assessed guideline awareness, usage, and pharmacological management practices for dementia in the oldest old and frail across Europe. METHODS: An online anonymous survey was distributed in 2023 to the European Geriatric Medicine Society Dementia Special Interest Group and their contacts to investigate guideline awareness and pharmacological practices for the oldest old and frail. The CHERRIES checklist was followed for reporting. Responses were summarized using descriptive statistics and quotations of free text responses. RESULTS: Forty-nine responses from fourteen countries were received. A total of 76.6% were aware of a national dementia guideline and 86.9% applied it frequently. Acetylcholinesterase inhibitors (AChEIs) were generally used as a first-line treatment in mild-to-moderate Alzheimer's disease (AD) (91.6% and 93.4%). Memantine was added or replaced AChEIs as dementia severity progresses. Gingko biloba was considered in mild and moderate AD (23.6% and 22.7%, respectively). Off-label drug use was common in other types of dementia. 88.5% of respondents reported no difference in treatment compared with a younger population. CONCLUSION: There was awareness of various dementia guidelines, but none addressed the management of the oldest old and frail. Most respondents did not adapt their practices for this group, but many reported off-label treatments which resulted in non-evidence-based prescribing, overprescribing, and a lack of deprescribing. European consensus to guide the management of dementia in this complex population is needed.