In Hungary the number of low birth-weight new-born babies is about 8200 in a year, while the frequency of for preterm birth is 8.2%. The infant mortality among the low birth-weight babies is higher, than among the normal weight babies. Every efforts are used to decrease the number of preterm births. Researches have been carried out since decades on finding its possible risk factors. A possible risk factor for low birth-weight babies may be the chronic periodontal infection. The publication provides a review of recently published evidences of the potential association between periodontal infection and preterm low birth-weight.