Background: There is growing evidence showing that a number of complex human diseases are caused or are at least influenced by periodontal diseases. Such diseases include cardiovascular diseases, respiratory diseases, diabetes mellitus, and osteoporosis. Aim: The aim of the present study was to evaluate periodontal diseases as a risk factor for preterm low birth weight infants. Methods: A case‑control study with a selection ratio of 1:1 was performed using 150 cases and 150 controls, who delivered their babies at Vanivilas Hospital, Bangalore, India, over a 3‑months period from January 2012–March 2012. Cases were defined as mothers delivering an infant weighing less than 2,500 gms and born before 37‑weeks gestation. Controls were mothers delivering an infant weighing more than 2,500 gms and born after 38‑weeks gestation. Patients were evaluated for age, socioeconomic status, obstetric risk, nutritional status, maternal morbidity, infections, toxic exposure, antenatal care, infant characters, through hospital records and personal questionnaire by incharge team members. Oral examination was performed using Extent and severity index, Sulcus Bleeding Index. Results: Cases and controls did not reveal any significant difference when compared for age, socioeconomic status, obstetric risk, nutrition, maternal morbidity, and antenatal care. Periodontal disease was more severe and extensive in cases when compared with control and the difference was statistically significant (P<0.001). Bleeding index scores were higher in cases as compared to control and was statistically significant (P<0.001). Conclusion: Within the limits of this study, it is concluded that a poor periodontal health status of the mother may be a potential risk factor for a preterm low birth weight.