A new DNA probe assay (PACE 2, Gen-probe) was compared with cell culture for the detection of Chlamydia trachomatis in 909 women attending the Royal Women's Hospital, Melbourne, Victoria. The DNA probe assay had a sensitivity of 86.2%, a specificity of 99.9% and a positive predictive value of 96.2% in a population with 3.2% prevalence, indicating that it may be a suitable alternative to culture for the detection of C. trachomatis in specimens from the genital tract.