Several analyses of the neurological features of Behcet's disease (BD) have concluded that there are significant racial differences in its clinical expression. Other series, however, failed to elicit such differences. We aimed to describe in this retrospective survey the frequency, nature and relationship to systemic disease of the neurological features in a cohort of BD patients of Caucasian origin. We searched hospital records from nine District General or Regional Centre hospitals in south-west Great Britain and identified 22 individuals of Caucasian ethnic origin with neuro-BD, with a mean of 10 years follow-up per patient - the largest 'western' case series with the longest period of follow-up reported. We found that presentation with neurological features was commoner in our patients (23%) than Middle Eastern series (3-10%). Seizures (27%) were likewise commoner (0-5%), as was optic neuritis (9% compared with 1-2%). Two patients developed movement disorders (chorea and parkinsonism), which have only been rarely reported. Of further clinical significance, we noted that non-neuropsychiatric features: oral ulceration, intraocular inflammation and skin lesions - were virtually always present or exacerbated during neurological complications. Ethnicity - or conceivably environment - may play a significant role in the manifestation of neurological BD.