Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia increasing the risk of stroke in fivefold. Improving knowledge at its development and prevention is crucial for AF patient management. This study aimed to predict the thrombogenesis in left atrium (LA) under AF by a multi-physics approach coupling a 3D transient profile of realistic electrophysiological activity, oscillatory mechanical effects and a biochemical model for thrombogenesis. The local mechanical effects from detailed AF activity disturbed the blood flow pattern, resulting in pro-thrombotic zones in left atrial appendage apex, in contrast with simplified AF model (rigid walls), that could lead to overestimation of pro-thrombotic zones.1.