New technology has made it possible to identify cardiogenic cerebral emboli more easily and reliably. In recent years echocardiography, and in particular transesophageal echocardiography, has become the gold standard for the identification of cardiogenic sources of emboli, whereas transcranial Doppler is an important technique for the detection of cerebral emboli. Treatment strategies are better established and more accurate, if more complex, since the completion of large randomized trials. For primary prevention of stroke in elderly patients with nonvalvular atrial fibrillation, warfarin is generally indicated, yet in patients aged 60-75 years with no risk factors, aspirin may be sufficient. Warfarin is hazardous in older high-risk patients even at the 'low intensity' of the anticoagulation regimen; even lower doses are therefore being tested. Heparin and aspirin are indicated for short-term treatment of acute myocardial infarction, whereas for long-term treatment aspirin is still the drug of choice. However, if mobile left ventricular thrombi are present, warfarin is superior and new studies have shown its effectiveness for all myocardial infarction survivors. Combined treatment of warfarin and aspirin appears to be most effective in patients with mechanical prosthetic valves.