Atrial fibrillation (AF) is the most common cause of cardioembolism. An update on secondary prevention strategies, used to protect patients from the risk of stroke in many common cardiac conditions, is presented in the paper. The main line of actions of stroke prevention in cardioembolism is mostly connected with antithrombotic drugs, but also other, more invasive, techniques are quickly emerging. Also the classic pharmacological prevention with coumarins may soon be overcome by new generation anticoagulants. Is an aggressive treatment of Patent Foramen Ovale (PFO) always recommended? One of the main challenges of the future years will be to understand competitiveness between old and new preventive strategies.