Since the 1990s, evidence has been raised that there is an association between maternal periodontal disease and undesirable gestational events, for example low birth weight; this issue is controversial. Objective. To evaluate whether there is an association between maternal periodontitis and low birth weight (LBW). Methods. A case-control study was carried out on 951 mothers that had been cared for by the Brazilian Unified Health System in Petrolina-PE and Juazeiro-BA, Brazil. The case group (n = 269) consisted of mothers of newborns with birth weight <2500 g and a control group (n = 682) of mothers of newborns with birth weight ‡2500 g. An interview was realized, using a questionnaire as well as a full mouth examination to diagnose the periodontal condition. Women who had at least four teeth with probing depth ‡4 mmand clinical attachment loss ‡3 mm, with bleeding on probing at the same site, were diagnosed with periodontitis. The birth weight was obtained through the hospital book record. The main association was evaluated using the multivariate regression model, considering confounders. Results. The frequency of periodontitis was 16.4% (case group) and 17.4% (control group). Periodontitis did not show an association with LBW (ORcrude = 0.92; 95% CI = 0.63–1.35), even after adjustment for the following confounders: maternal age, pre-gestational body mass index, number of pre-natal consultations, number of pregnancies, maternal schooling level, smoking habit during pregnancy and hypertension (ORadjusted = 1.00; 95% CI = 0.61–1.68). Conclusion. The findings of this study showed no association between maternal periodontal disease and low birth weight, even after appropriate adjustments for confounding factors.