Left atrial appendage closure (LAAC) is recommended to decrease the stroke risk in patients with atrial fibrillation and contraindications to anticoagulation. However, age-stratified data are scarce. The aim of this study was to provide information on the safety and efficacy of LAAC, with emphasis on the oldest patients. A nationwide, prospective, multicentre, observational registry was established by 53 French cardiology centres in 2018-2021. The composite primary endpoint included ischaemic stroke, systemic embolism, and unexplained or cardiovascular death. Separate analyses were done in the groups <80 years and ≥80 years. Among the 1053 patients included, median age was 79.7 (73.6-84.3) years; 512 patients (48.6%) were aged ≥80 years. Procedure-related serious adverse events were non-significantly more common in octogenarians (7.0% vs 4.4% in patients aged <80 years, respectively; p=0.07). Despite a higher mean CHA DS -VASc score in octogenarians, the rate of thromboembolic events during the study was similar in both groups (3.0 vs 3.1/100 patient-years; p=0.85). By contrast, all-cause mortality was significantly higher in octogenarians (15.3 vs 10.1/100 patient-years, p<0.015), due to a higher rate of non-cardiovascular deaths (8.2 vs 4.9/100 patient-years, p=0.034). The rate of the primary endpoint was 8.1/100 patient-years overall with no statistically significant difference between age groups (9.4 and 7.0/100 patient-years; p=0.19). Despite a higher mean CHA DS -VASc score in octogenarians, the rate of thromboembolic events after LAAC in this age group was similar to that in patients aged <80 years. ClinicalTrials.gov Registry (NCT03434015).