Neonatal health is an important issue to consider in the context of public health. One of the indicators used to evaluate neonatal health is birthweight. It refers to the weight of the neonate at the time of birth. There are several factors that affect birthweight. There factors are genetic, medical, environmental, socio-economic, and demographic factors. It is important from a public health perspective to focus on preventable factors that could mitigate or eliminate the negative effects of these factors on neonatal health. Low or high birthweight could have an impact not only in the neonatal period but also in childhood. This study evaluates socio-economic and demographic determinants of birthweight, and reviews the effects of both low and high birthweight on neonatal health based on previous researches.