Outpatient statin use is known to reduce the risk of recurrent ischemic stroke of atherothrombotic etiology, but it is not known whether statins have similar effects in ischemic stroke associated with atrial fibrillation (AF). We examined the relationship between outpatient statin adherence and the risk of recurrent ischemic stroke in patients with or without AF in a large integrated healthcare delivery system. Among 6,283 patients with ischemic stroke discharged on a statin over a 5 year period, 1,486 (23.7%) had a diagnosis of AF at discharge. Statin adherence rates, measured as percentage of days covered (PDC), averaged 85% (88% for AF patients and 84% for non-AF patients). We observed up to three years after the initial stroke, with an average of two years follow up. In multivariable survival models, after controlling for age, gender, race/ethnicity, and key medical comorbidities, higher statin adherence was found to strongly predict a reduced risk of recurrent ischemic stroke (Figure). In the second year post-stroke, the hazard ratio (HR) associated with a 10% increase in PDC was 0.93 (95% C.I. 0.89-097). The relationship between statin adherence and reduced stroke rates was similar in AF patients (HR 0.94, 95% C.I. 0.84-0.98) and non-AF patients (HR 0.93, 95% C.I. 0.88-0.98). These findings support the use of outpatient statins in all ischemic stroke patients, irrespective of stroke etiology (atherothrombotic vs. atrial fibrillation).