Background Lactobacilli in the vagina protect women from bacterial vaginosis (BV) and other potentially harmful microorganisms. BV is the imbalance in the normal vaginal flora which is predominantly Lactobacilli. It is the most common cause of vaginal discharge and is associated with adverse pregnancy outcome. One of the mechanisms employed by Lactobacilli to fight BV associated organism is the production of an antimicrobial substance known as bacteriocin. Objectives: To determine the Nugent score of women attending antenatal clinic in LUTH, isolate and identify Lactobacilli from vagina of the pregnant women, assay for bacteriocins from the Lactobacilli isolated, correlate the production of bacteriocin with Nugent score of the pregnant women, assess the pregnancy outcome of the pregnant women and correlate it with bacteriocin production and Nugent scores Methods A total of 300 women who were receiving antenatal care in Lagos University teaching Hospital were recruited in this study. High vaginal swabs were collected from them for assessment of Nugent score to diagnose BV and for culture on MRS agar and blood agar for isolation of Lactobacilli. The Lactobacilli were identified using Matrix Assisted Laser Desorption Ionization Time-of-flight Mass Spectrometry (MALDI-TOF MS) and bacteriocin was extracted using the chloroform extraction method.