Neurologic events associated to antiphospholipoid syndrome (APLS) are not uncommon, but ischemic stroke due to acute carotid thrombosis, is a rare presentation of this syndrome. We report a case of a 48 years old female patient, without evidence of atherothrombosis or other vascular pathology, who presented an ischemic stroke due to acute thrombosis of the left internal carotid artery. The occlusion was diagnosed by Duplex scan and magnetic resonance angiography (Ds+MRA). The patient was anticoagulated and experienced total regression of her neurologic symptoms after a week. Ds+MRA were performed again and confirmed re-establishment of normal flow of internal carotid artery. A thorough clinical investigation confirmed the diagnosis of APLS (the association of a major thombotic event and high anticardiolipoid IgG antibody titers in three blood samples). The patient has been submitted to oral anticoagulation for three years and has not experienced new neurologic or thrombotic events.