OBJECTIVE: The study was undertaken to determine the accuracy of the liquid-based Papanicolaou (Pap) smear in the detection of Trichomonas vaginalis organisms in women. STUDY DESIGN: Two hundred three consecutive patients who had the liquid-based Pap smear also underwent a culture for T vaginalis. A wet mount was performed if symptomatic. Results were analyzed for sensitivity, specificity, and positive and negative predictive values. RESULTS: Forty-four patients (21.6%) had a positive culture. On the liquid-based Pap smear, 28 patients (13.8%) were positive for T vaginalis, showing a sensitivity of 61.4%, a specificity of 99.4%, a positive predictive value of 96.4%, and a negative predictive value of 90.8%. When wet mount and culture were compared, a sensitivity of 50%, a specificity of 93%, a positive predictive value of 77%, and a negative predictive value of 80% were obtained. CONCLUSION: The presence of T vaginalis organisms, as stated by the liquid-based Pap smear pathology report, is accurate and warrants treatment without further testing.