Benign angiopathy of the central nervous system (BACNS) is a subset of primary angiitis of the central nervous system (PACNS) with favorable outcome, not requiring prolonged immunosuppression. We retrospectively studied the clinical characteristics and prospectively assessed long-term outcome in a cohort of BACNS patients. Patients meeting the clinical description for BACNS, evaluated and treated by a single investigator, were included. Data on demographics, signs and symptoms, laboratory studies, neuroimaging, brain biopsy, treatment, and complications were recorded. The long-term assessment included a phone interview utilizing the Barthel index and a specifically designed cognitive index. Sixteen cases met the inclusion criteria. Mean age was 40 years (range 10-66 years) with female:male ratio of 4.3:1 and a mean followup period of 35 months (0-128 months). Headache was the most common presenting symptom, seen in 88% of the cases, followed by focal symptoms (63%), and diffuse symptoms (44%). All patients had highly abnormal cerebral angiography, and magnetic resonance imaging abnormalities were present in 77% (10 of 13). Severe cerebral spinal fluid (CSF) abnormalities were present in 1 patient (7%). All followup cerebral angiography showed marked improvement. Recovery was demonstrated in 94% of the patients, 6% relapsed, and there were no deaths. Of patients assessed by the Barthel index, 71% showed no disability and 29% had mild disability. There is a PACNS subset characterized by acute presentation (most commonly headache), normal to mildly abnormal CSF findings, female predominance, and highly abnormal cerebral angiography (reversible after treatment), requiring less intensive treatment than has been traditionally used.