Aim: Prematurity and low birth weight are major causes of neonatal morbidity, mortality and long-term disability. The purpose of this study was to determine if an association exists between periodontal disease and preterm birth (PT).Material and methods: 59 females from the delivery ward at St. Mary's Health Center, St. Louis, MO. Group I had 29 women who had Preterm birth (PT). Group II had 30 women whose babies were born full term (T). Full-mouth periodontal examination performed. Data collected about risk factors: race, maternal age, pregnancy complications; infections/inflammation; number of previous pregnancies and chemical abuse. Mothers were considered to have moderate to severe periodontal disease if ≥ 10% of sites measured ≥ 5 mm probing depth. Nominal logistic regression analysis used to calculate the odds of having a preterm birth infant having moderate to severe periodontal disease while adjusting for other risk factors.Results: After adjustment for smoking, preeclampsia, and infections/inflammation other than periodontitis, a statistically significant association was found between preterm birth and moderate to severe periodontitis (odds ratio = 5.8, 95% CI = 1.2-37.5, p = 0.04). Conclusion:Moderate to severe periodontal disease may be an independent risk factor for preterm birth.