Forty randomly selected patients with systemic lupus erythematosus (SLE) were studied by clinical and serologic parameters and magnetic resonance imaging (MRI). Abnormal MRI was found in 15/40 patients (37.5%): all 15 cases showed multiple widespread small-sized areas of increased signal in T2 in the white matter; in one of these patients MRI also displayed a large area with a reduced signal in T1 and an increased signal in T2 involving both the white and the gray matter. Among the 15 patients with abnormal MRI, only 7 had neuropsychiatric symptoms. The presence of MRI changes was highest in patients with organic type symptoms and was associated to the highest disease severity scores. A long-term follow up of asymptomatic patients would be useful to establish whether the application of MRI is appropriate for the assessment of CNS involvement in SLE.