In a follow-up study 60 hands of 49 patients were examined 1-12 years after operation for carpal tunnel syndrome. The syndrome was diagnosied in the majority of cases on clinical examination only. Paresthesia, hypesthesia or anesthesia in the 3 1/2 radial fingers of the hand are typical signs. Some patients complained of severe pain irradiating towards the elbow and shoulder. The method of surgical treatment is described in detail. Of the 49 patients only 2 were dissatisfied with the result. Both patients suffered from stenosing arteriosclerotic disease of the peripheral arteries of the hand and their pain and paresthesia were relieved by thoracic sympahtectomy. 58% of patients had complete relief from from symptoms while the remaining cases had a significant reduction of symptoms and were satisfied with the result of surgical treatment. The results were better in those patients who were operated on soon after the onset of symptoms. From the results of this study it is clear that surgical treatment of carpal tunnel syndrome provides good results and that surgical treatment should be recommended without delay if conservative treatment is unsuccessful.