ABSTRACT Objective: to assess Pap smear performance in bacterial vaginosis diagnosis in women of childbearing age. Method: a cross-sectional, retrospective study carried out in a health unit in a city in the interior of São Paulo. The study included information from 1,173 women who underwent collection of Pap smear and Gram-stained vaginal smears (reference standard test for bacterial vaginosis diagnosis) and analysis based on the Nugent score, from January 2013 to June 2020. Secondary data collected from the information and internal control systems were used. Results: the prevalence of bacterial vaginosis in the sample was 31.8%. The degree of agreement between the two diagnostic methods by the Kappa index was 0.54, considered moderate, with a value <0.001. Sensitivity was 55.2% and specificity was 94.1%, with accuracy of 81.7% and positive predictive value of 81.4% and negative of 81.8%. Conclusion: Pap smear showed agreement with the reference standard of 0.77, however, does not replace the Gram-stained vaginal smear, but can be used as an auxiliary method for bacterial vaginosis diagnosis.