The linear naevus sebaceous syndrome of Feuerstein-Mims belongs to the phacomatoses and classically is composed of a linear cutaneous lesion associated with mental retardation and epilepsy, sometimes also with ocular dystrophies. During an unusually long follow-up of 32 years of such a case, which is reported here, the late occurrence of additional ocular and intracranial pathology are demonstrated: conjunctival and bulbar tumours with progressive deterioration of visual acuity, bilateral intracranial arachnoidal cysts, dilatation and tortuosity of the middle cerebral artery. As a consequence of these observations the prognosis in cases with this syndrome has to be given with special caution.