Background Though engaging patients with atrial fibrillation (AF) in understanding their stroke risk is encouraged by guidelines,little is known regarding AF patients perceived stroke risk or its relationship with oral anticoagulation (OAC) use.We aim to identify factors associated with underestimation of stroke risk among older patients with AF and relate this to OAC use.Methods Data are from the ongoing SAGE (Systematic Assessment of Geriatric Elements)-AF study,which included older patients (＞ 65 years) with non-valvular AF and a CHA2DS2-VASc score of≥ 2.Participants reported their perceived risk of having a stroke without OAC.We compared the perceived risk to CHA2DS2-VASc predicted stroke risk and classified participants as "over" or "under" estimators,and identified factors associated with underestimation of risk using multiple logistic regression.Results The average CHA2DS2-VASc score of 915 participants (average age: 75 years,47％ female,86％ white) was 4.3 ± 1.6,43％ of participants had discordant predicted and self-reported stroke risks.Among the 376 participants at highest risk (CHA2DS2-VASc score ≥ 5),46％ of participants underestimated their risk.Older participants (≥ 85 years) were more likely and OAC treated patients less likely to underestimate their risk of developing a future stroke than respective comparison groups.Conclusions A significant proportion of study participants misperceived their stroke risk,mostly by overestimating.Almost half of participants at high risk of stroke underestimated their risk,with older patients more likely to do so.Patients on OAC were less likely to underestimate their risk,suggesting that successful efforts to educate patients about their stroke risk may influence treatment choices.