Some our previous research works on bacterial adhesion to vaginal cells in the different phases of the menstruum showed that adhesion changes depending on changing environmental conditions. We therefore considered interesting to extend our investigations to anaerobic flora, in the light of recent observations intended to attribute an important role to anaerobic flora in the pathogenesis of vaginitis. The results obtained so far indicate that the maximum adhesion capability is found in the middle of the menstruum. The very low adhesion of bacteria belonging to the Leptothrix genus remains substantially unaltered throughout the menstruum. Low adhesion is also found in sporogenic bacteria, whereas the coccoid ones have a stronger adhesion, particularly about the middle of the menstruum. With lower pH values adhesion of the anaerobic flora is enhanced, whereas in the final phase of the menstruum, with higher pH values, adhesion is reduced. Competition tests evidence a stronger adhesion of coccoid as compared to bacillar types.