Cognitive dysfunction represents one of several neurological and psychiatric complications of Systemic Lupus Erythematosis (SLE). Additional manifestations of nervous system involvement subsumed under the term neuropsychiatric SLE (NPSLE) include cerebrovascular disorder, seizures, psychosis, acute confusional state, anxiety and mood disorders. Neuropsychological investigations have facilitated the identification and description of cognitive impairment in SLE and NPSLE. Salient findings from studies of SLE-related cognitive dysfunction are reviewed with respect to neuroimaging procedures, indices of disease activity, and potential moderator variables. Data on cognitive functioning are also discussed in reference to other disease aspects including fatigue, sleep disturbance, and impact on health-related quality of life (HRQL). To date, neuropsychological functioning has been studied extensively, albeit separately from other commonly reported SLE-related symptoms. Future research may profit from investigating relationships between cognitive impairment, sleep disturbance and fatigue and their collective impact on functional capacity and quality of life.