Background: Low birth weight is a major determinant of mortality, morbidity and disability in infancy and childhood and also has a long-term impact on health outcomes in adult life. Objectives: The present study was undertaken with the objectives of assessment of occurrence of low birth weight babies delivered in NRS Medical College & Hospital and to find out the role of different sociodemographic and pregnancy related factors influencing low birth weight. Method: A descriptive, observational study was conducted in the postnatal ward of the Hospital. All mothers who delivered during the study period were interviewed and relevant record was reviewed. Results: 38% of the babies had low birth weight. Proportion of teenage mothers were higher in case of low birth weight babies compared to the mothers of normal birth weight babies ( 27.7% Vs 17% ). 72.3% of the LBW babies were from family with per capita income < Rs 3000/- compared to 37.7% normal birth weight babies. 67.7% of mothers of low birth weight babies had last child birth within 3years compared to 33% of normal babies. 10.7% of the mothers of LBW babies had <3 ANC visits compared to 1.8% in other group. 22.6% of the mothers consumed <100 Folifer tablets and 23.1% smoked tobacco during the antenatal period who delivered LBW babies compared to 1.8% and 2.8% respectively in their counterparts. Conclusion: Magnitude of low birth weight is still high and various unfavourable socio-demographic, antenatal and obstetric factors increased the risk of delivering low birth weight baby.