Abstract Background An Advance Care Plan (ACP) outlines patient preferences for future treatment for a time when capacity is lacking. With our ageing population and rising dementia prevalence, ACPs are of increasing relevance and importance; however, very few are created each year. This study aims to explore General Practitioner (GP) perspectives on ideal timing, facilitators, and barriers to ACPs. Methods To date, ten GPs with a range of clinical experience have been purposely sampled from the Irish College of General Practitioners database. Semi-structured interviews were conducted by phone, video call, or in person, concurrently recorded, and subsequently transcribed. The Braun and Clarke method of thematic analysis was utilised, and coding was performed using NVivo software. Results All GPs spoke to the importance of ACPs for care of those with dementia and believed GPs are ideally placed to have these discussions. Two themes arose regarding timing of discussion: (1) routine proactive discussion prior to potential cognitive issues arising and (2) discussion within a few appointments of diagnosis. Identified barriers to ACP include: (1) lack of patient awareness of ACPs, (2) lack of GP education on ACPs, (3) difficulty predicting disease progression, (4) poor family dynamics, (5) short appointment times, and (6) lack of remuneration. Identified facilitators include: (1) patient’s acceptance of death and understanding of diagnosis, (2) use of an established template to guide discussion, (3) presence of a trusted family member, (4) long appointment times and (5) remuneration. Conclusion There was universal agreement on the importance of ACPs. Inclusion of ACP teaching in the curriculum for undergraduate medical education and postgraduate GP training should be strongly considered. There is need for heightened public awareness of the Assisted Decision-Making Act and ACPs. Further qualitative and quantitative research is needed to explore this issue nationally and identify how it has been resolved internationally.