Ischemic stroke due to emboli originating from the heart or thoracic aorta is called a cardiovascular source of embolism, which accounts for 15%–30% of all ischemic strokes. Additionally, an increasing number of cryptogenic strokes, which account for 45% of non-lacunar ischemic strokes, are classified as Embolic strokes of an undetermined source (ESUS). Cardiovascular emboli can lead to clinically significant morbidity and mortality through arterial occlusion, which results in infarction or transient ischemic attacks (TIA). Typical ischemic stroke shows imaging/pathological evidence of infarction and symptoms of focal neurological deficit lasting >24 h. A paradoxical embolus is a systemic infarct in which the source of the embolus is supposed to be from the venous system; it bypasses the pulmonary circulation using an intracardiac shunt and goes across into the arterial circulation. In this chapter, we will discuss the general concepts of stroke and potential cardioarterial sources of embolism, focusing on the role of echocardiography.