A chemiluminescent-labeled DNA probe (Gen-Probe PACE 2 System) for detection of Chlamydia trachomatis in endocervical specimens was evaluated. For each specimen, tissue cell culture, direct immunofluorescent staining (DFA), and DNA probe assay were performed. Thirty of 318 (9.4%) specimens were positive for C. trachomatis. The sensitivities, specificities, and positive and negative predictive values of the DNA probe compared with cell culture were 93%, 98%, 85%, and 99%, respectively, and for DFA these same values were 81%, 99%, 83%, and 99%, respectively. The Gen-Probe PACE 2 System is a reliable method for the rapid detection of endocervical chlamydial infection.