In Indonesia, the incidence of low birth weight is still very high. Ministry of health is conducting programmes to reduce low birth weight from 14 per cent to 7 per cent by the year of 2000. In optimizing the results of these efforts, some factors associated with maternal health and nutrition are important to be known. This study based on a cohort prospective study in 20,002 pregnant women in Bogor, West Java, discusses a number of factors of socio-economic, medico-obstetrics, and food consumption. The maternal factors significantly associated with low birth weight infants included low formal education (illiteracy), chronic major illness, previous pregnancy with complications such as abortion or low birth weight, interval of pregnancies less than sic months, high blood pressure with edema and protein in urine, very severe anemic or hemoglobin concentration below 8 g%, and low dietary intake. These informations are important in relation to the need for actions to be taken in improving prenatal care through community active participation in health services.