A few studies have suggested that higher body mass index (BMI) is associated with an increased susceptibility to bacterial vaginosis (BV); however, the results are conflicting. A recent study, published in Sexually Transmitted Diseases, analyzed female sex workers aged 16-45 years, participating in an open, prospective cohort study from 2000 to 2014. Up to 2 years of follow-up were included per participant. BMI of ≤18.5 was categorized as underweight, 18.5-24.9 as normal, 25-29.9 as overweight, and ≥30 as obese. BV was assessed with the help of Nugent scores. Generalized estimating equations were used to estimate relative risks of the association between BMI and BV. Nearly 32.1% (n=625) of 1,946 women had BV at baseline. Half of the women were overweight (31.1%, n=606) or obese (20.1%, n=391). Participants contributed 14,319 follow-up visits. When adjusted for age, compared to women with normal BMI, overweight (adjusted relative risk [aRR] 0.91, 95%CI 0.81-1.02) and obese (aRR 0.82, 95%CI 0.71-0.94) women were found to be at lower risk for BV.Obese women were found to have a nearly 20% lower risk of BV compared to women with normal BMI. Potential mechanisms for this effect, including probable effects of diet, obesity-associated changes in the gut microbiome, and systemic estrogen levels, thus need to be explored.