The prevalence of patent foramen ovale is approximately 20% in the global population. In patients under the age of 55 years, it has been proven as a cause of acute ischemic embolic stroke of otherwise undetermined source. We present a case of a 25-year-old patient who experienced an acute stroke of dominant hemisphere due to internal carotid artery occlusion.The patient underwent mechanical thrombectomy, followed by acute intracranial stenting due to persistent subocclusion of internal carotid artery. Further diagnostic investigations revealed a significant patent foramen ovale. During subsequent follow-up periods, the patient encountered multiple transient ischemic attacks despite receiving antithrombotic therapy. The indicated angiography examination revealed in-stent stenosis and thrombosis, which were resolved after optimal medical treatment. Following patent foramen ovale closure, the patient remained free from further neurological events during the subsequent two-year follow-up periods. This case emphasizes the necessity of comprehensive diagnostic evaluations in young individuals with stroke and underscores the importance of prudent slection of medical therapies.