The prevalence and incidence of atrial fibrillation (AF) increase with age. However, older patients often are denied oral anticoagulation (OAC), especially if they are "very elderly" (age ≥90 years) and perceived to be high risk for bleeding, for example, those with a history of intracranial hemorrhage (ICH), gastrointestinal bleeding (GIB), or chronic kidney disease. The purpose of this study was to investigate the effectiveness and safety of OAC in this high-risk, very elderly group. We used the Taiwan National Health Insurance Research Database to identify high-risk, very elderly subjects taking OAC, either warfarin or a non-vitamin K antagonist oral anticoagulant (NOAC), and compared them to non-OAC users for the composite net clinical endpoint of ischemic stroke, ICH, major bleeding, or mortality. We studied 7362 subjects (mean age 92.5 years), of whom 1737 were taking NOACs, 670 warfarin, and 4955 non-OACs. Compared to non-OACs, warfarin was associated with a higher risk of the composite endpoint (adjusted hazard ratio [aHR] 1.163; 95% confidence interval [CI] 1.052-1.287), whereas NOACs were associated with a lower risk (aHR 0.763; 95% CI 0.702-0.830). After propensity matching, NOACs were associated with a lower risk of events compared to non-OACs or warfarin, whereas warfarin had a similar risk compared to non-OACs. Warfarin was associated with a similar or even higher risk of composite clinical outcomes compared to non-OACs. NOACs were associated with a lower risk of composite endpoint compared to warfarin or non-OACs, and their use still should be considered in these high-risk, very elderly AF patients.