Background: Both periodontal disease and bacterial vaginosis may cause adverse pregnancy outcomes. This study evaluated the association between periodontal disease and bacterial vaginosis. Materials and Methods: Data from 3569 women enrolled in the Longitudinal Study of Vaginal Flora were used. Periodontal disease, defined as greater than three sites with ≥4 mm attachment loss, was assessed by specially calibrated hygienists at baseline. Positive bacterial vaginosis status was based on a Nugent Gram stain score ≥7. Pairs of independent variables were compared with Pearson's χ2 and risk ratios were calculated through log-binomial regression. Results: Twenty-eight per cent of women with bacterial vaginosis had periodontal disease compared with 22% without, corresponding to 1.29 (95% CI: 1.13, 1.47) times greater risk of periodontal disease among women with bacterial vaginosis. In adjusted analysis the risk ratio dropped to 1.23 (95% CI: 1.08, 1.40). Receptive oral sex with an uncircumcised partner was associated with 1.28 times (95% CI: 0.97, 1.69) the risk for periodontal disease compared with receptive oral sex with a circumcised partner, though the association is not statistically significant. Conclusions: In this population, there is a small but significant association between periodontal disease and bacterial vaginosis and a possible trend between receptive oral sex with an uncircumcised partner and periodontal disease. © 2010 John Wiley & Sons A/S.