For patients with acquired heart valve lesions with increased risk for intracardiac thrombosis and consequent cardiogenic embolism there is consensus that oral anticoagulation therapy improves the overall prognosis. In mitral valve lesions anticoagulation is necessary after manifestation of atrial fibrillation or in cases of unstable sinus rhythm. The risk for thromboembolic events is increasing parallel to the enlargement of the left ventricular enddiastolic diameter, the left atrial size and dropping cardiac index. Spontaneous echo contrast (so called smoke like echos) indicate a prethrombotic state. In these cases an intensive anticoagulation is indicated. Aortic valve lesions require anticoagulation after manifestation of atrial fibrillation, the first manifestation of a thromboembolism or of spontaneous echo contrast. The risk for thromboembolism is increasing parallel to the reduction of left ventricular pump function. Life long oral anticoagulation therapy should be managed by use of the International Normalized Ratio (INR), and should be individualized taking into account patient related cardiac morphology and physiology, which may predispose to cardiogenic embolism. The target INR can range between 2.0 and 4.0.