We investigated risk factors for central nervous system (CNS) involvement in systemic lupus erythematosus (SLE), in 32 such patients individually matched 1 : 3 to 96 control SLE patients without CNS events. Univariate analysis showed that CNS involvement was significantly associated with the antiphospholipid syndrome (APS) as well as its features: arterial thrombosis, recurrent fetal loss, livedo reticularis and IgG anticardiolipin (aCL) antibodies in high titres. Other potential associations included cutaneous vasculitic lesions, thrombocytopenia, positive ANA, anti-SS-B/La and low serum levels of C(3) and C(4) complement components, while articular manifestations and discoid rash were significantly less common in patients with neuropsychiatric (NP) disease. In multivariate modeling, CNS involvement was strongly associated with cutaneous vasculitic lesions OR 33, 95% CI 1.5-720) and arterial thromboses (OR 13, 95%CI 0.82-220), and negatively related to the presence of articular manifestations (OR 0.015, 95%CI 0.00-0.17) and discoid rash (OR 0.004, 95%CI 0.00-0.35). Associations with APS-related arterial thromboses and vasculitis point to the importance of arterial vascular pathophysiology in the pathogenesis of NP disease in SLE. Patients with articular manifestations and discoid rash are at very low risk of NP events. Patients with an adverse SLE disease profile may require closer observation and may be the target group for studying pre-emptive interventions.