Ischemic strokes are characterized by high morbidity and high mortality and disability rates. The etiology is thought to be mostly closely related to large vessel atherosclerosis, cardiogenic embolic dislodgement, and hypertensive small artery lesions, but the cause of 30-40% of ischemic strokes is still unknown. PFO (patent foramen ovale) is a common congenital cardiac malformation with a prevalence of approximately 26% in the normal population. Studies have shown a close association between patent foramen ovale and ischemic stroke, with patent foramen ovale found in approximately 40% of stroke patients of unknown origin. During fetal life the foramen ovale acts as a physiological channel allowing blood to flow from the right atrium into the left atrium, maintaining fetal circulation. After birth, as pulmonary circulation is established, blood flow and pressure in the left atrium increase, causing functional closure of the foramen ovale. 70-75% of the foramen ovale is completely closed within 2 years of birth, while a quarter of individuals eventually have an anatomic foramen ovale that is not closed. An accurate understanding of patent foramen ovale should be a dynamic left-right interatrial channel, a living valve-like structure formed by unfused primary and secondary septum, rather than just a “hole”. Because of this valve-like structure, the direction of blood flow is unidirectional in most of the unclosed patent foramen ovale in clinical practice, with right-to-left shunts occurring when right atrial pressure is greater than left atrial pressure. In contrast, an atrial septal defect is a real “hole” in the atrial septum, and blood flow can flow in both directions in the right and left atria. The possible mechanisms of stroke due to patent foramen ovale are: (1) paradoxical embolism, in which an embolus, either venous or fatty, air, etc., passes through the patent foramen ovale and enters the arterial circulation and causes a cerebrovascular embolic event; (2) atrial arrhythmia associated with patent foramen ovale leading to intra-atrial thrombus formation; (3) patent foramen ovale with atrial septal tumor. The septal tumor is an anatomic factor closely associated with stroke, which can oscillate from side to side with the heartbeat rhythm, increasing the likelihood of fractional flow and thrombosis. One study showed that patients with an unclosed foramen ovale combined with an atrial septal tumor had a 20-fold increased risk of recurrent stroke; (4) The hypercoagulable state associated with an unclosed foramen ovale may induce venous embolism and increase the likelihood of paradoxical emboli. The main methods to detect patent foramen ovale include transthoracic wall echocardiography (TTE), transesophageal echocardiography (TEE), transcranial Doppler ultrasound (TCD) foam test, intracardiac ultrasound (ICE) and dynamic enhanced magnetic resonance imaging. TEE is considered to be the gold standard for the diagnosis of patent foramen ovale. Currently, the treatment of patients with ischemic stroke associated with an unclosed foramen ovale is mainly antithrombotic medication and closure of the unclosed foramen ovale. There is no clinical evidence to suggest a difference between anticoagulation and antiplatelet therapy in the prevention of recurrent stroke and death in patients with ischemic stroke associated with unclosed foramen ovale and atrial septoma. Clinical recommendations also vary widely. In 2006, the American Stroke Association/American Heart Association guidelines for patients with ischemic stroke or transient ischemic attack recommended antiplatelet therapy for patients with patent foramen ovale alone, but anticoagulation was recommended if the patient also had venous thrombosis or hypercoagulable state. Open-heart surgical occlusion is one of the effective ways to treat patent foramen ovale, but it is gradually being replaced by percutaneous interventional patent foramen ovale occlusion due to its more invasive nature. Since 1974, when a double-disc device was used to seal the atrial septal defect, various devices have been used in the interventional closure of patent foramen ovale, proving their safety and efficacy. However, no significant advantage of interventional device occlusion over drug therapy has been found in studies of stroke prevention associated with patent foramen ovale. Clinical randomized controlled trials on the efficacy of percutaneous interventional occlusion of patent foramen ovale versus pharmacologic therapy for the prevention of stroke associated with patent foramen ovale have not been completed, and therefore there are no guidelines or recommendations for the choice of treatment modality. In general, percutaneous interventional occlusion of patent foramen ovale is considered a reasonable option for patients with recurrent ischemic stroke after medical treatment. Until more clinical evidence and randomized controlled trials are available, there is still a lack of optimal treatment options, and therefore a multidisciplinary and individualized treatment plan based on the patient’s specific situation is the best treatment option. Health education should also be provided to patients so that avoiding or reducing daily behaviors that can trigger disease attacks will help to reduce the incidence of diseases associated with patent foramen ovale, especially associated ischemic strokes.