Low birth weight has been a cause of concern since times immemorial. But the identification of factors associated with it came only after many careful observations by many learned men and women at different times and places. Despite its Universal presence, it acquires significant importance in the developing countries of the world where social, demographic and environmental factors, almost always act as villains competing with the poor standards of healthcare in these countries. LBW is closely associated with fetal and perinatal mortality and morbidity, inhibited growth and cognitive development, and chronic diseases later in life. At the population level, the proportion of babies with a LBW is an indicator of a multifaceted public-health problem that includes long-term maternal malnutrition, ill health, hard work and poor health care in pregnancy. On an individual basis, LBW is an important predictor of newborn health and survival and is associated with higher risk of infant and childhood mortality. This study seeks to identify some of the factors associated with low birth weight seen in institutional deliveries at Katihar in a bid to explore the strategies for prevention.