A 40-year-old male, treated with radiotherapy and supraophthalmic intracarotid artery (ICA) ACNU infusion for glioblastoma in the right occipital lobe, developed cerebral infarction secondary to vasculopathy manifesting as hemiparesis 3 months after a second ICA injection. The initial diagnosis was focal neurotoxicity, but angiography revealed severe vasospasm of the anterior choroidal artery. The symptoms improved gradually with therapy for the vasospasm. Angiography is required to discriminate vasospasm and focal neurotoxicity as a complication of ICA injection of antineoplastic agents.