In Western countries, stroke is the second cause of death and the first cause of disability. Cardiogenic embolism is the most frequent cause of recurrent strokes. Nonvalvular atrial fibrillation (NVAF) is the most common source of cardiogenic embolism, with a stroke recurrence rate of about 10% per year. Randomised trials have shown that anticoagulation and aspirin are safe in patients with NVAF, leading to 70% and 22% risk reduction of strokes, respectively. Many potential candidates to anticoagulation fail to receive the appropriate treatment for primary and secondary prevention. More efforts should be spent to increase the number of treated subjects, in order to achieve effective prevention on stroke.