Background : Probiotics enhance human well-being. They can be used either as a preventive approach to maintain the microbiota or as an add-on treatment for some diseases. The lactobacilli constitute the predominant vaginal microorganism and have been associated with a beneficial effect in vaginal health by protecting and controlling the vaginal microbiota against bacterial vaginosis, vaginal candidiasis, and urinary tract infection. Results: We investigated the probiotic properties of the new vaginal Lactobacillus crispatus IP174178 strain isolated from healthy women. Lactobacillus crispatus IP174178 strain was identified by 16S rRNA sequencing and by biochemical characterization. L. crispatus IP174178 is Gram positive, Catalase negative, ADH negative, and an H 2 0 2 (5 mM) and lactic acid (D-lactate 6 g/l, L-lactate 3 g/l) producer, with a strong adherence capacity. Its sensitivity to antibiotics was evaluated. Conclusions: The native strain L. crispatus IP174178 showed natural antagonistic properties against vaginal pathogens ( Gardenerella vaginalis , Candida spp.) which is potentiated in its commercial live biotherapeutic product Physioflor ® . The L. crispatus IP174178 strain and its live biotherapeutic product Physioflor ® can thus be considered a good probiotic candidate for the prevention of vaginal infections.