PURPOSE: To suggest the characteristic MR features and to evaluate the usefulness of MR imaging for the diagnosis of neuro-Behcet's disease. MATERIALS AND METHODS: We retrospectively reviewed the MR findings of clinically confirmed neuro-Behcet 's disease in eight patients (M:F = 7:1) ranging in age from 28 to 47 (average, 36) years. The findings were analyzed in terms of the most frequently occurring sites, signal intensities, contrast enhancement, and the changing patterns seen on follow-up MR examination. RESULTS: Seven of the eight patients had parenchymal brain lesions and the other had dural sinus thrombosis without brain parenchymal brain abnormality. In descending order of frequency, lesions involved the pons, midbrain, medulla oblongata, internal capsule, basal ganglia, thalamus, temporal lobe, and corpus callosum. The brain stem was involved in six patients, five of whom showed extensive involvement of the entire stem. In five patients, brain stem lesions showed supratentorial involvement, and in one, involvement of this region only was noted. Signal intensities of the lesions were poorly defined and extensive, especially in the brain stem, and usually showed prolongation of both T1 and T2 relaxation time. Three patients underwent follow-up examination, and this showed that while most lesions had disappeared in time, some had become small and cavitary. Initial MR examination showed that three patients had newly developed lesions as well as cavitary foci, suggesting the recurrence of disease. Contrast enhancement was noted in five of seven patients (71%), and various types, including nodular, linear, marginal, and ring. CONCLUSION: The MR features of neuro-Behcet 's disease were fairly characteristic, and in clinically unsuspicious patients might be diagnostically useful.