Despite the many advances in medicine, the rate of preterm birth has not significantly decreased in the United States over the past several decades. In fact, the rate rose in 2003 to more than 12% of all births in the United States. This equates to over half a million premature births in the United States alone. Consequently, the identification of risk factors for preterm birth which are amenable to intervention would have far-reaching and long-lasting effects. There is emerging evidence of a relationship between periodontal health and adverse pregnancy outcomes, particularly preterm birth/preterm low-birth-weight infants. Therefore this chapter explores the putative association between periodontal disease and infant prematurity, as well as the results of intervention studies which treated periodontal disease in order to reduce the incidence of prematurity. Of 31 published studies, 22 show a positive association between premature birth and periodontal disease. Ongoing studies are addressing the efficacy of periodontal treatment for decreasing the incidence of infant prematurity.