The prevalence of atrial fibrillation (AF) increases with age. The prescription of anticoagulation in very elderly patients is controversial and sometimes underused. Our objective is to report the incidence and predictors of major bleeding in anticoagulated nonagenarian patients with non valvular atrial fibrillation (NVAF). We analyzed a large multicentre registry of anticoagulated nonagenarian patients diagnosed with NVAF from three health areas of Spain, between 2013 and 2017. Predictors of major bleeding were studied with a competing risk analysis and the impact of major bleeding with a time-dependent mortality analysis. The incidence rate of major bleeding was 5 per100 person-year (95% Confidence Interval CI: 4.59–6.35), similar in the group of patients with vitamin K antagonists (VKAs) and direct oral anticoagulants (DOAC). In the VKAs group we found as predictors of major bleeding: previous admission for bleeding (sub-distribution hazard ratio sHR 3.25, 95% CI: 1.48–7.13), creatinine (sHR 1.38, 95% CI: 1.16–1.64,) and control out-of-range INR (sHR 1.90, 95% CI: 1.02–3.55). In DOAC group, male sex (sHR 1.92, 95% CI: 1.18–3.13) and the history of previous admission for bleeding (sHR 2.60, 95% CI 1.33–5.06) were found as a predictor. The HAS-BLED was not associated with major bleeding. Major bleeding was associated with increased mortality in both VKAs and DOAC groups without significant differences. We found an incidence rate of major bleeding with relative low values, similar in those treated with VKAs and those treated with DOAC, with different predictors of major bleeding in each group. Major bleeding was associated with increased mortality, with no significant difference by oral anticoagulation therapy (OAT). •The incidence rate of major bleeding in nonagenarian patients underwent oral anticoagulation therapy (OAT) is low.•Different predictors of bleeding were found for  vitamin K antagonists (VKAs) and direct oral anticoagulants (DOAC). 3) HAS-BLED was not a predictor of major bleeding in our study with nonagenarians.