Antiphospholipid antibodies (APL) are associated with venous and arterial thrombosis in SLE patients. Various thrombotic and non-thrombotic neurological manifestations have been reported in SLE but whether or not they are related to the presence of APL antibodies remains uncertain. To assess the possible association between neurological involvement in SLE and APL antibodies, IgG anticardiolipin antibodies (IgG ACL) were looked for using an ELISA technique in 92 consecutive SLE patients seen over a one-year period. Other APL determinations included VDRL and lupus anticoagulant (LAC) testing using APTT and the diluted thromboplastin time. Twenty-four SLE patients presented with neurological manifestations (40 episodes): 15/24 (62.5%) were found positive for APL antibodies (11 VDRL, 8 LAC, 7 ACL antibodies) versus 22/68 patients (32%) without neurological symptoms (p < 0.01). APL antibodies antedated neurological symptoms in 13/16 cases. Neurological manifestations were subsequently divided into 3 groups: thrombotic (n = 14), psychosis and convulsions (n = 15), miscellaneous (n = 10). No correlation was found between APL antibodies and any of the 3 subgroups. Among patients with neurological SLE, APL antibodies were present in two with valvular heart disease, as well as in seven with a history of either deep vein thrombosis, livedo reticularis or miscarriage. Among 7 patients with thrombocytopenia and neurological symptoms, 6 had APL antibodies. These data suggest that APL syndrome is associated with neuro-ophthalmological manifestations of SLE regardless of whether or not the mechanism of neurological involvement is thrombotic. SLE patients with APL antibodies may be at risk for future neurological manifestations. However, it is still questionable that APL positivity has definite therapeutic consequences.