Background : Infant mortality rate is one of the most important health index in societies for which low birth weight plays the most important role. The present study was carried out in Qom province to determine this index and its related factors.

Materials and methods : For this cross sectional study 1927 newborns were selected from different private and public delivery units. A questionnaire was completed and infant’s mothers were interviewed and pediatricians examined Infants. Finally, those LBW newborns were entered for analysis.

Results : Of 1927 newborns, 11.8% weighed under 2500 grams, of these 47% had mothers aged less than 18 years and 10% had mothers aged more than 35 years. 51% of these infants were female. There was a significant correlation between previous history of abortion and LBW infant delivery, however, we could not find any association between maternal occupation and level of education with LBW infants.

Conclusion : The high prevalence of LBW infants in Qom province is noticeable. Further studies are strongly recommended.