Carpal tunnel syndrome (CTS) is a relatively benign condition whose incidence in the general population is about 10%. The clinical interest of CTS lies in the differential diagnosis of the syndrome relative to other conditions that may have a greater impact on the patient's overall health. The scientific interest lies in deciphering the pathophysiological mechanisms of proximal limb manifestations of patients with CTS, defining the cause of the lesion, and establishing the relationship between symptoms and electrophysiological findings. Electrodiagnosis is fundamental for CTS diagnosis, follow-up and research. Nevertheless, no universally accepted methodological criteria are available. Therapeutic advice at present is based more on clinical impression than on objective, reasoned evaluation. Serial clinical and electrophysiological studies are needed to evaluate treatment efficacy, functional regeneration, and clinico-electrophysiological correlation.