The personality characteristics of 24 consecutive patients undergoing psycho-surgery for incapacitating anxiety disorders were assessed prospectively using a self-report personality inventory. The main findings were: absence of negative personality changes after surgery, significant postoperative changes towards normalization on the majority of the scales, and significant symptomatic relief in 80% of the cases. The changes on scales reflecting anxiety proneness were conspicuous in patients suffering from "pure" anxiety disorders, as compared with those suffering from obsessive-compulsive disorder (OCD). In OCD patients, correlations were obtained between changes in brain metabolism studied with positron emission tomography and changes in personality scores. It is concluded that negative personality changes are not likely to occur after capsulotomy.