BACKGROUND: Carpal tunnel syndrome is a common disorder, for which several surgical treatment options are available. However, there is no consensus on the most effective method of treatment. OBJECTIVES: To compare the efficacy of the various surgical techniques in relieving symptoms and promoting return to work and/or activities of daily living and to compare the occurrence of side-effects and complications in patients suffering from carpal tunnel syndrome. SEARCH STRATEGY: We conducted computer-aided searches of the Cochrane Controlled Trials Register (Cochrane Library, Issue 1, 2000), MEDLINE(searched January 1966-March 2000) and EMBASE (searched January 1988-February 2000), and tracked references in bibliographies. SELECTION CRITERIA: Randomised controlled trials comparing various surgical techniques for the treatment of carpal tunnel syndrome. DATA COLLECTION AND ANALYSIS: Study selection, assessment of methodological quality and data abstraction were performed by two reviewers independently of each other. MAIN RESULTS: Sixteen studies were included in the review. The methodological quality of the trials was fair to good. However, the application of allocation concealment was mentioned explicitly in only two trials. Many studies failed to present the results in sufficient detail to enable statistical pooling. Pooling was also impeded by the vast variety of outcome measures that were applied in the various studies. None of the existing alternatives to standard open carpal tunnel release seem to offer better relief from symptoms in the short- or long-term. There is conflicting evidence about whether endoscopic carpal tunnel release results in earlier return to work and/or activities of daily living than open carpal tunnel release. REVIEWER'S CONCLUSIONS: There is no strong evidence supporting the need for replacement of standard open carpal tunnel release by existing alternative surgical procedures for the treatment of carpal tunnel syndrome.