The aim of this review was to identify, assess, collate, and analyze existing research that has made a direct contribution to aiding understanding of the ethical and decision-making issues related to the use of advance care directives for people with dementia and/or other major neurocognitive disorders and/or their surrogate decision-makers on treatment. The Web of Science, Scopus, PubMed, CINAHL, Academic Search Ultimate, and MEDLINE databases were searched between August and September 2021 and July to November 2022 limited to primary studies written in English, Spanish, or Portuguese. Twenty-eight studies of varying quality that addressed related thematic areas were identified. These themes being support for autonomy in basic needs (16%), making decisions ahead/planning ahead and upholding these decisions (52%), and support in decision-making for carers (32%). Advance care directives are an important mechanism for documenting treatment preferences in patient care planning. However, the available literature on the topic is limited in both quantity and quality. Recommendations for practice include involving decision makers, promoting educational interventions, exploring how they are used and implemented, and promoting the active involvement of social workers within the healthcare team.