In this prospective study the neuropsychological and psychosocial function of 64 patients undergoing surgical resection of cerebral arteriovenous malformations was examined prior to surgery (T1), one month post-surgery (T2) and one year post-surgery (T3). A mild but widespread cognitive decline was observed pre-operatively. There was a trend toward decreased neuropsychological function at T2. All neuropsychological tests showed a trend toward improvement at T3 compared with both pre-operative (generally not statistically significant) and early post-operative values (generally significant). Patients were assessed for change between testing times. At T2 patients were more likely to have deteriorated than improved, whereas at T3 the group which had altered from baseline were more likely to have improved than deteriorated. Deterioration in some verbal/language tasks was more common for left sided AVMs. Outcome did not differ significantly for patients presenting with haemorrhage. Psychosocial function was unchanged at late follow-up for the majority of patients.