Posterior leukoencephalopathy typically denotes neurotoxicity from immunosuppressive agents, malignant hypertension or eclampsia. It has not been documented in central nervous system angiitis. We present three cases associated with isolated cerebral angiitis after review of all cases of isolated CNS angiitis from 1998 to 2000. Additional lesions beyond the posterior occipital lesions became evident in two cases. A cerebral angiogram and possibly brain biopsy to detect isolated angiitis should be considered in patients with posterior leukoencephalopathy of unknown etiology.