Few MRI studies have been performed on subjects with Von Recklinghausen's neurofibromatosis. This not very well-known disease present lesions which in many cases do not appear on CT scans but may be detected by MRI. The nature of such lesions is still controversial. This paper will describe the case of a 7 year-old girl with neurofibromatosis. MRI examination revealed altered signals in some areas: in the basal nuclei, in the brainstem and in the white matter of the cerebellar hemispheres.