A new diagnostic test for carpal tunnel syndrome. A new test, called the carpal compression test, consists of application of direct pressure on the carpal tunnel and the underlying median nerve. The results of the Tinel percussion test, the Phalen wrist-flexion test, and the new test were evaluated in thirty-one patients (forty-six hands) in whom the presence of carpal tunnel syndrome had been proved electrodiagnostically, as well as in a control group of fifty subjects. For the diagnosis of carpal tunnel syndrome, the carpal compression test was found to be more sensitive and specific than the Tinel and Phalen tests. 