A case of the unusual clinical condition of cerebral coenurosis, the unique parasitic disease that is localized only in the CNS, is reported. The patient had repeated attacks of transient hemiparesis due to intracranial arteritis which was demonstrated by several angiographic studies. The CSF showed a discreet lymphocytosis and increased immunoglobulins. This inflammatory reaction which preceeded the manifestations of the intracranial mass can be explained by the parasitic foreign bodies, the liberation of somatic and metabolic parasitic toxins and the immunological reaction of the organism. The arteritis of the basal intracranial vessels was probably secondary to the inflammatory reaction of the leptomeninges. In presence of the rare association of meningovascular disease and an expanding intracranial lesion a parasitic condition due to a larval stage of Cestodes (Hydatidosis, Cysticercosis, Coenurosis) should be always considered.