Atrial fibrillation (AF) is associated with a high risk of stroke and its prevalence increases in subjects aged ≥65 years. After an ischemic stroke, the use of standard monitoring methods may underestimate the detection rate of AF. Recent studies demonstrated a fourfold to sixfold increase in the detection of AF with prolonged ECG monitoring as compared to standard cardiac monitoring in patients with cryptogenic stroke. Hence, it is very likely that even patients having a first atherothrombotic or lacunar stroke with high burden of vascular risk factors are exposed to increased risk of developing AF in the subsequent years and AF may be the cause underlying possible recurrent strokes.