Twenty-one unselected SLE patients were examined with Magnetic Resonance Imaging (MRI) for cerebral areas of high signal intensity (HSI). Nine patients (42.9%) had HSI and 6 (28.6%) had large (> or = 6 mm) lesions suggestive of cerebral involvement. Despite the lack of correlation among these lesions and clinical or immunological features, the SLEDAI and ECLAM indices were correlated to the number of large lesions (p < 0.002). Our findings suggest that brain MRI may be useful in the evaluation of SLE patients, not only those with evident neurologic symptoms, but also asymptomatic subjects with high disease activity indices.