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ABSTRACT: Introduction & Objective: Median nerve entrapment in the wrist is the most common entrapment neuropathy and is called carpal tunnel syndrome (CTS). Conventional electrophysiologic studies evaluate only the myelinated fibers. Sympathetic skin response (SSR) is a well-established test for evaluation of the unmyelinated sympathetic fibers. This study was designed to evaluate the sympathetic fibers in CTS. Materials & Methods: Fifty four patients with carpal tunnel syndrome and 78 healthy subjects were enrolled in this study. Conventional electrodiangostic studies and SSR were performed in all the subjects with standard method. Results: Latency of the SSR in healty subjects was 1520.21±87.25 ms and 1637.11 ± 281.13 ms in patients. Conclusion: Unmyelinated sympathetic fibers are involved in CTS and SSR which may, along with other conventional electrophysiologic tests, help in diagnosis of CTS.