Twenty five patients with conservatively treated cerebral arteriovenous malformation were followed up for a mean of 10-6 years after diagnosis. The follow up included neuropsychological examination. Bleeding did not occur after the time of diagnosis. Three patients had moderate to severe neurological deficits, five had moderate to severe intellectual impairment. Nineteen had an unaffected occupational status. It is concluded that the outcome in conservatively treated patients may be no worse than in surgically treated patients.