This study reports the relationship between three clinical tests in the diagnosis of carpal tunnel syndrome and the stages of nerve compression. Assessments of 158 patients with carpal tunnel syndrome were reviewed retrospectively. 77% of patients had at least one of the clinical signs present. The incidence of positive pressure-provocative and Phalen's tests were similar and more likely to occur in combination than separately. Tinel's sign was more likely to be positive in the later stages of nerve compression. Our results suggest that the presence or absence of a provocative test is dependent upon the severity of the nerve compression.