•Long-term benefits of anticoagulants for oldest-old stroke survivors were investigated.•Over one-year period, all recurrent stroke was ischemic rather than hemorrhagic.•Long-term anticoagulant therapy for oldest-old stroke survivors may be justified. Long-term anticoagulant therapy in oldest-old persons poses the risk of bleeding complications. The aim of this study was to evaluate the long-term benefits of anticoagulant therapy for oldest-old stroke survivors with AF. Patients with atrial fibrillation (AF) who were 90 years of age or older and were prescribed an anticoagulant on discharge were identified from a set of data from a prospective follow-up registry of 1,484 consecutive patients admitted for ischemic stroke or transient ischemic attack over a 4-year period beginning in 2014. The outcome measures were stroke and death following discharge. Of the 77 identified patients with AF who were 90 years of age or older, 71 were prescribed an anticoagulant (median age 93 years, 73% women). Thirty-nine patients were given a direct oral anticoagulant (DOAC) (median age 92 years, 69% women), and 32 were given warfarin (median age 93 years, 78% women). During the follow-up period (median 466 days), 9 patients (13%) had stroke recurrence (recurrence rate: 14%/year), and 25 patients (35%) died (mortality rate: 33%/year). The type of all recurrent strokes was ischemic, and no fatal bleeding occurred. There was no difference in the incidence of recurrent strokes according to anticoagulant type (DOAC 15%/year, warfarin 13%/year, P = 0.743), but a higher proportion of patients on warfarin died (21% vs. 47%, P = 0.002). Given that a higher proportion of oldest-old stroke survivors with AF on anticoagulant therapy have recurrent ischemic stroke rather than hemorrhagic stroke, long-term anticoagulant therapy may be justified for secondary stroke prevention.