Silent or asymptomatic atrial fibrillation (AF) is common. It can occur in patients with symptomatic AF, where silent episodes often outweigh symptomatic episodes. It can also occur in patients who experience no symptoms at all, or who have non-specific AF symptoms. Silent AF may present with a stroke (approximately 9% of all ischaemic strokes) or with heart failure due to tachycardia-induced cardiomyopathy which responds to control of ventricular rate. Silent AF is often found during routine clinical examination by pulse palpation or routine electrocardiogram (ECG), or with implanted cardiac electronic devices which continuously sense atrial activity. Management of implanted device-detected AF is debated as the stroke risk is lower than symptomatic AF, particularly when episodes are brief. Silent AF may be detected by opportunistic screening, either at a single time point or by multiple patient-initiated recordings over 2 weeks. AF screening may utilize pulse palpation, photoplethysmography, modified sphygmomanometers, or handheld ECG devices. Because an ECG is required for a diagnosis, handheld ECG recorders with automated AF detection are now recommended. Screen-detected AF is not low risk and requires antithrombotic therapy. Screening for AF to prevent stroke has been shown to be cost-effective.