Aim Atrial fibrillation (AF)‐related cardioembolic stroke is a serious problem in the aging society. The present study examined the clinical characteristics and outcomes of AF‐related cardioembolic stroke in patients aged ≥80 years. Methods Between September 2011 and April 2014, consecutive patients with ischemic stroke and AF were retrospectively extracted from the multicenter database. Clinical characteristics were compared between patients aged ≥80 years and <80 years. Multivariate cox proportional hazard models were used to estimate hazard ratios and 95% confidential intervals on 90‐day mortality for age of ≥80 years. Results A total of 253 patients aged ≥80 years (87 men, 86.4 ± 5.0 years) and 196 patients aged <80 years (134 men, 70.4 ± 7.1 years) were included. Patients aged ≥80 years were more frequently female, and more likely to have higher premorbid modified Rankin Scale score (mRS), lower body mass index, previous history of stroke, prior antiplatelet therapy, congestive heart failure, and persistent AF. Patients aged ≥80 years had higher initial National Institutes of Health Stroke Scale score and were more likely to have occlusion of the cervicocephalic arteries, but less likely to receive thrombolysis. Patients aged ≥80 years had a higher mRS and mortality after 3 months. Age of ≥80 years was a significant predictor of 90‐day mortality after adjustment for sex (hazard ratio 2.20, 95% confidential interval 1.25–4.09), but was no longer significant after further adjustment for other clinical characteristics and stroke severity. Conclusions In AF‐related cardioembolic stroke, patients aged ≥80 years had different clinical characteristics and poorer outcome compared with patients aged <80 years. Geriatr Gerontol Int 2017; 17: 708–713.