ABSTRACT. Objectives: To determine whether older people with advance directive for euthanasia (ADEs) are stable in their advance desire for euthanasia in the last years of life, how frequently older people with an ADE eventually request euthanasia, and what factors determine this. Design: Mortality follow-back study nested in a cohort study. Setting: The Netherlands. Participants: Proxies of deceased members of a cohort representative of Dutch older people (n = 168) and a cohort of people with advance directives (n = 154). Measurements: Data from cohort members (possession of ADE) combined with after-death proxy information on cohort members' last 3 months of life. Multiple logistic regression analysis was performed on determinants of a euthanasia request in individuals with an ADE. Results: Response rate was 65%. One hundred forty-two cohort members had an ADE at baseline. Three months before death, 87% remained stable in their desire for euthanasia; 47% eventually requested euthanasia (vs 6% without an ADE), and 16% died after euthanasia. People with an ADE were more likely to request euthanasia if they worried about loss of dignity. Conclusion: The majority of older adults who complete an ADE will have a stable preference over time, but an advance desire for euthanasia does not necessarily result in a euthanasia request. Writing an ADE may reflect a person's need for reassurance that they can request euthanasia in the future.