Lupus anticoagulant antibodies and anticardiolipin antibodies are acquired circulating immunoglobulins that interact with phospholipids. These factors may exert anticoagulant properties in vitro and so interfere with coagulation tests that use phospholipids. These antibodies are not, however, associated with a hemorrhagic diathesis. Indeed, despite their name and their in vitro anticoagulant properties, they have been associated right from the earliest reports with systemic and cerebral thromboembolic episodes. We report the clinical and instrumental findings in a patient with ischemic stroke and anticoagulant antibodies in the serum.