OBJECTIVE:The aim of this study was to evaluate the efficacy of radial extracorporeal shock wave therapy on pain, functionality, and electrophysiological measurements in carpal tunnel syndrome. METHODS: Between June 2021 and January 2022, a total of 66 wrists in 45 participants with mild-to-moderate carpal tunnel syndrome were included in this double-blind, prospective, randomized, placebo-controlled study. Patients were randomized into two groups, namely, the radial extracorporeal shock wave therapy (group 1, n=33) and the sham radial extracorporeal shock wave therapy (group 2, n=33). Night splints and tendon nerve gliding exercises were given to all participants. The participants were evaluated at baseline and the first month after treatment. Participants were evaluated using a visual analog scale, the Boston Carpal Tunnel Questionnaire, Leeds Neuropathic Symptom and Symptom Assessment, and electrophysiological examinations. RESULTS: A total of 37 participants (a total of 55 wrists, radial extracorporeal shock wave therapy n=27, and sham radial extracorporeal shock wave therapy n=28) completed the study. After the intervention, there was a significant decrease in visual analog scale values (p<0.001) and a significant increase in Boston Carpal Tunnel Questionnaire scores (p<0.001) and Leeds Neuropathic Symptom and Symptom Assessment scores (p<0.001). In electrophysiological measurements, there was a significant decrease in median nerve sensory (p=0.002) and motor (p=0.003) distal latency, and a significant increase in median nerve sensory conduction velocity (p=0.026) was found in the radial extracorporeal shock wave therapy group. CONCLUSION: This study shows that radial extracorporeal shock wave therapy has positive effects on pain, functionality, and electrophysiological measurements for mild-to-moderate carpal tunnel syndrome 1 month after application.