A 39-year-old man with livedo reticularis, optic neuropathy and acute ischemic encephalopathy (Sneddon's syndrome) had antiphospholipid antibodies. This primary antiphospholipid antibody syndrome was unsuccessfully treated by anticoagulation, corticosteroids and plasma exchanges. Despite a frank reduction of the circulating antibody titers after plasma exchanges, no improvement of the neurological symptoms was observed. Death was related to a systemic complication when the antibody titer was at its lowest level. This case provides further evidence that effective treatment for stroke associated with antiphospholipid antibodies is still wanting.