A prospective randomized study was undertaken of 50 consecutive patients undergoing surgery for idiopathic carpal tunnel syndrome to determine the value of splintage of the wrist following open carpal tunnel release. Patients were randomized to either be splinted for 2 weeks following surgery or to begin range-of-motion exercises on the first post-operative day. Subjects were evaluated at 2 weeks, 1 month, 3 months, and 6 months after surgery by motor and sensory testing, physical examination, and a questionnaire. Variables assessed included date of return to activities of daily living, dates of return to work at light duty and at full duty, pain level, grip strength, key pinch strength, and occurrence of complications. Patients who were splinted had significant delays in return to activities of daily living, return to work at light and full duty, and in recovery of grip and key pinch strength. Patients with splinted wrists experienced increased pain and scar tenderness in the first month after surgery; otherwise there was no difference between the groups in the incidence of complications. We conclude that splinting the wrist following open release of the flexor retinaculum is largely detrimental, although it may have a role in preventing the rare but significant complications of bowstringing of the tendons or entrapment of the median nerve in scar tissue. We recommend a home physiotherapy programme in which the wrist and fingers are exercised separately to avoid simultaneous finger and wrist flexion, which is the position most prone to cause bowstringing.