Great importance has been attributed to birth weight all over the world because it is considered as one of the best predictors of prenatal survival and a good indicator of quality life. The objective of this study was to determine the prevalence of low birth weight babies (LBW) and factors related to it in Baghdad city. A cross sectional study was carried out in four general hospitals in Baghdad city, Iraq. A total of 225 newborn babies, alive, singleton and without congenital malformation were selected randomly from these four general hospitals.The result of the study showed the prevalence rate of low birth weights was 21.3%. Mothers’ educational level, monthly family income, mothers with chronic hypertension, mothers with history of previous low birth weight infants and anemic mothers were significantly associated with low birth weight babies (P= 0.03, 0.01, 0.02,