We used validated outcome instruments to measure symptoms, disability, and health-related quality of life in 58 patients with carpal tunnel syndrome (CTS). The patients completed the CTS instrument before and 6 weeks, 3 months, and 6 months after surgery and the Short Form-36 (SF-36) before and 3 months after surgery. The size of clinical change detected by each outcome measure was estimated by the standardized response mean (mean change/ standard deviation of the change). Large improvement was observed for the CTS symptom scale (mean standardized response, 1.4-1.9) and function scale (0.8-1.1). Improvement in SF-36 scales was large for pain (1.0) and moderate for physical role, mental health, and the physical component summary (0.5-0.6). Compared with the general population SF-36 norms (n = 2,181), CTS patients had significantly worse scores for physical functioning, physical role, pain, vitality, and the physical component summary before surgery. After surgery, SF-36 scores had normalized except for physical role and the physical component summary.