To study the value of postoperative splinting after open carpal tunnel surgery, we randomly selected 82 wrists for 4 weeks of postoperative immobilization or no immobilization. The distributions of scar discomfort or pain and "pillar pain" were equal in the two groups both at 6 weeks and 6 months. Median sick leave was 6 weeks in both groups. Median VAS values for persistent discomfort and pain at 2 weeks, 6 weeks and 6 months were similar in the two groups. Grip strength was reduced compared to preoperative values by about 20% and keypinch strength by about 10% in both groups at 6 weeks and had returned to normal by 6 months. Pinch between the thumb and the tips of fingers 4 and 5 was considerably reduced postoperatively, but similar in both groups. We conclude that 4 weeks of postoperative immobilization confers no detectable benefit.