BackgroundHalf of those undergoing major lower limb amputation for peripheral arterial disease die within 1 year. Advance care planning reduces days in hospital and increases the chance of dying in a preferred place.AimTo investigate the prevalence and content of advance care planning for people having a lower limb amputation due to acute or chronic limb-threatening ischaemia or diabetes. Secondary aims were to explore its association with mortality, and length of hospital stay.DesignA retrospective observational cohort study. The intervention was advance care planning.Setting/participantsPatients admitted to the South West England Major Arterial Centre between 1 January 2019 and 1 January 2021 who received unilateral or bilateral below, above, or through knee amputation due to acute or chronic limb-threatening ischaemia or diabetes.Results116 patients were included in the study. 20.7% (n = 24) died within 1 year. 40.5% (n = 47) had an advance care planning discussion of which all included cardiopulmonary resuscitation decisions with few exploring other options. Patients who were more likely to have advance care planning discussions were ≥75 years (aOR = 5.58, 95%CI 1.56–20.0), female (aOR = 3.24, 95%CI 1.21–8.69), and had multimorbidity (Charlson Comorbidity Index ≥5, aOR = 2.97, 95%CI 1.11–7.92). Discussions occurred more often in the emergency pathway and were predominantly initiated by physicians. Advance care planning was associated with increased mortality (aHR = 2.63, 95%CI 1.01, 5.02) and longer hospital stay (aHR = 0.52, 95%CI 0.32–0.83).ConclusionsDespite a high risk of death for all patients in the months following amputation, advance care planning occurred in fewer than half of people and mostly focused on resuscitation.