We report three cases of postherpetic vasculopathy in immunologically compromised patients. Two had ophthalmic herpes zoster, contralateral to the physical signs, and the third case developed after disseminated herpes zoster. The initial CT images consisted of small ischemic infarcts in capsular regions and basal ganglia. The arteriography showed images consistent with vasculitis or thrombosis of great vessels of the Willis' polygon, which were ipsilateral to the herpetic lesion in two cases. In one patient the neurological defect remained stable, while the other two developed new ischemic episodes, all in the same cerebral hemisphere. It can be assumed from the delayed development of neurologic disease after cutaneous lesions that some cases go unnoticed if the zoster infection is not specifically looked for in retrospect.