Marfan syndrome is a systematic genetic disease of the connective tissue. The cardiac affection would predict the prognosis and ischemic stroke might complicate it. The purpose of this work is to discuss the mechanisms of the ischemic stroke in Marfan syndrome which have to be considered in all young patients of ischemic strokes. We report the case of a 17-year-old male patient who presented with right hemiparesis with brachio-facial dominance, hemihypoesthesia and Broca's aphasia; these symptoms were followed by partial right somato-motor epileptic seizure. The cerebral computed tomographic (CT) scan demonstrated early signs of ischemic stroke in the left Sylvian artery. Cardiovascular examination revealed a systolic murmur in the mitral site. Marfan syndrome with infectious endocarditis complicated by ischemic stroke was diagnosed. However, the family pathological history was negative. The Marfan syndrome diagnosis was approved considering the following criteria: Ligamentous hyperlaxity, crystalline ectopia and mitral valve prolapsus with mitral insufficiency. The patient benefited of antibiotherapy for 4 weeks. The patient underwent sessions of motor physical therapy and orthophonic rehabilitation. Then, cardiac surgery was carried out and valvuloplasty was performed. The surgical treatment confirmed the presence of mitral insufficiency and prolapsus of the big mitral valve and multiple friable anterior-posterior vegetations with broken cordage of the small mitral valve. Replacement of the mitral valve was achieved, and the post-surgery follow-ups were simple. The diagnosis of Marfan syndrome was based on well-defined criteria. The evolution of the patient was marked by a complete improvement of the cardiac and motor deficits, and disappearance of the Broca's aphasia. A fibroelastic disease such Marfan syndrome has to be considered in unexplained ischemic stroke in all young patients. Hence, the diagnosis of Marfan syndrome involves an anticipation of the neurovascular complications by early cardiovascular care.