The lupus anticoagulant, an immunoglobulin of the IgG or IgM class, is one of a group of antiphospholipid antibodies. Although an anticoagulant in vitro, its action in vivo is that of a procoagulant. This procoagulant activity may involve many organ systems including the nervous system. Thus far cerebral thrombosis, spinal thrombosis, chorea and Guillain-Barré syndrome have been described in association with the lupus anticoagulant. Although the lupus anticoagulant is an uncommon cause of neurological disease, it must be considered, especially in a setting of a prolongation of the common pathway of coagulation, thrombosis and other autoimmune phenomena.