Thirty SLE patients underwent clinical neurological examination, electrophysiological studies, cerebral computer tomographic (CT) scans, and blood sampling. Nineteen patients (63%) had clinical neuropsychiatric and 10 patients (33%) had clinical neuromuscular manifestations. Migrainous headache affecting 11 patients (37%) was the most prevalent clinical manifestation. Electrophysiological testing revealed abnormal electroencephalography in 10 patients (33%). Abnormal electromyography and nerve conduction velocity were found in 13 (43%) and 7 (24%) patients respectively. Abnormal visual evoked response was detected in 2 patients. Cerebral CT scans displayed cerebral atrophy in 20 patients (71%), while 6 patients (21%) had cerebral infractions. Disease activity assessed by two different tests revealed a higher prevalence of cerebral infarctions, classical migraine, muscular weakness, and pathological electromyography and nerve conduction velocity in the higher disease activity groups. Cerebral infarctions were only found among anti-Ro negative patients, but apart from this, no significant association could be found between coagulopathy, circulating immune complexes, cryoglobulins, routine immunological tests, medication, and any clinical, electrophysiological or cerebral CT pathology.