Some authors have shown that hyperhomocysteinemia (HHCY) is a risk factor for stroke/TIA mainly in patients with associated other risk factors such as hypertension, dyslipidemia, smoking and carotid atherosclerosis. The mechanism through HHCY acts is only postulated but experimental evidence suggest that endothelial dysfunction generated by reactive oxygen species, platelet activation and thrombus formation play a key role in the pathophysiologic mechanisms of HHCY. It has also been demonstrated that HHCY can represent an independent risk factor for venous thromboembolism and the association between HHCY with factor V Leiden further increase the risk of deep venous thrombosis. Here we reported a case of A 16 year-old woman presented to our emergency room complaining of headache and showing a right facial paresis, a mild defect of motility in her upper right arm, a slurred speech with NIHSS (National Institute of Health Stroke Scale) =7. Magnetic resonance study plus MRI venography were performed which showed an ischemic lesion in the left frontal area and occlusion of the longitudinal superior venous sinus. Her plasma levels of homocysteine was increased (91 µmol/L), so anticoagulation with LMWH and then with warfarin and a therapy with folic acid was started. After a cycle of rehabilitation she was discharged with full recovery. As stroke could have serious impact on the quality of life, HHCY should be considered in all patients with stroke or TIA and eventually treated