Background <p>People living with dementia often continue to take preventive medication until the end of their lives, largely with the aim of prolonging life. However, at the later stages of dementia, a palliative-only, symptom-controlling approach, may be more appropriate. Also, the efficacy of preventive medications in older people is often unclear and the side effects may have a negative impact on quality of life, yet these medicines are often not deprescribed.</p> Aim <p>To synthesise qualitative evidence of healthcare professionals’ and family members’ views on deprescribing preventive medication for people living with dementia.</p> Methods <p>The systematic review was conducted using the principles for systematic reviews of qualitative evidence provided by Cochrane. In May 2025, keywords were searched for in Embase, Health Management Information Consortium, MEDLINE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, PubMed, Open Access Theses and Dissertations, Web of Science, ProQuest, Cochrane Central Library and Google Scholar to identify suitable studies from pre-defined eligibility criteria. The Critical Appraisal Skills Programme was used for quality appraisal and Thomas and Harden’s qualitative thematic synthesis for synthesising findings.</p> Results <p>Eighteen studies were included. Five themes were identified: the decision-makers, reactive reasons to deprescribe, barriers and facilitators to proactive deprescribing, difficulties for family members and the timing of deprescribing decisions. Guidance is often unclear for this complex group, but guidance is unlikely to cover every individuals’ unique situation. Ideally, in practice, deprescribing should occur before someone gets to a stage when they can no longer communicate side effects and this may instigate more deprescribing discussions. To assist deprescribing, recording why a medication was started on the prescription could make it clearer whether to discontinue it at a later stage.</p> Conclusion <p>Deprescribing conversations are difficult for both healthcare professionals and family members. Future research could explore the role of advance care planning for deprescribing preventive medications, before someone is diagnosed with dementia, so decision-makers are aware of what the person would have wanted. This may make deprescribing less time-consuming, provide guidance and reduce the burden for the decision-makers.</p> Trial registration <p>PROSPERO CRD42023476394 (October 2023).</p>