This study involved 100 cases of carpal tunnel syndrome defined according to current electromyographic criteria. This investigation compared electromyographic data, in particular the speed of sensory conduction in the median nerve in the wrist with 8 clinical criteria, age, the duration of the disorder, the incidence and painful nature of nocturnal paresthesia observed, the incidence of diurnal paresthesia, Tinel's sign, Phalen's test, and the test of hyperextension of the wrist. After comparing these findings, two conclusions may be drawn: the identification of high-risk patients, who are persons over 70 years of age and the existence of a statistically significant correlation between the speed of sensory nervous conduction and Phalen's test. All other criteria examined have no bearing in predicting the severity of median nerve compression.