Abstract: The present invention relates to a method for in vitro diagnosis and follow-up of vaginal bacterial flora status in relation to the presence of bacterial vaginosis, and for monitoring its treatment where applicable, wherein the presence of bacterial vaginosis or failure of on-going treatment is determined if the concentrations of specific sequences present in a single copy in the DNA of the bacteria Atopobium vaginae and Gardnerella vaginalis in the DNA extracted from a vaginal discharge specimen from a patient are such that at least one of the following two conditions a) and b) are met: a) the concentration Ca of said DNA fragment of Atopobium vaginae is greater than or equal to 108 copies/mL, and b) the concentration Cg of said DNA fragment of Gardnerella vaginalis is greater than or equal to 109 copies/mL.