Paroxysmal atrial fibrillation (PAF) is often asymptomatic and increases the risk of ischaemic stroke. Detection of PAF is challenging but crucial because a change of treatment decreases the risk of ischaemic stroke. Post-stroke investigations recommend at least 24-h continuous cardiac rhythm monitoring. Extended monitoring detects more PAF but is limited by costs due to manual analysis. Interpretive software might be a reasonable screening tool. The aim was to validate the performance and utility of Pathfinder SL software compared to manual analysis.