Background: bacterial vaginosis is a vaginal infection most prevalent in the world. A study was conducted with the objective of to determine the prevalence of bacterial vaginosis in women of Medellin.Methods: cross sectional study, realized with 138.100 cytological records collected during 2010-2011. The information was analyzed in SPSS 20.0, with summary measures, frequencies, parametric and no parametric tests.Results: the average age was 37, in a range between 10 and 98 years. The bacterial vaginosis prevalence was 18,1% and statistically different in age groups, planning methods and area of residence studied. 41,5% didn’t present any planning method and only 2,3% used barrier method.Conclusion: the bacterial vaginosis was higher in adolescents, women that used Intrauterine device and live in Manrique, Santa Cruz and San Antonio de Prado area. This information is relevant for strengthening of health programs that seek identify a greatest risk groups and priority areas for education and care health.