There is growing evidence that the high prevalence of low-birth-weight (LBW) babies, a characteristic of many poor societies, can be significantly reduced through nutritional intervention programs. In order to increase the efficiency of these programs, pregnant women at risk of delivering LBW babies must be identified. Several risk scales have been extensively used in urban populations of developed countries. However, these indicators are of little use in poor communities, since most of them require expensive laboratory techniques, a long interview, at least two visits to a health center, and a precise estimation of gestational age. The present paper proposes several risk indicators of LBW, appropriate for use in areas with inadequate health resources. In a four-year longitudinal study of pregnant women from poor rural villages in Guatemala, mothers of LBW babies were found to be typically small in stature and head circumference. In addition, their houses tended to be of relatively poor quality. The proportion of LBW babies found among women at risk, as defined by these indicators, was significantly lower among women with similar characteristics receiving adequate food supplementation during pregnancy. Categories of high risk were based on maternal height, head circumference, and house quality. It is concluded that use of these categories will increase the efficiency of these programs without decreasing significantly their effectiveness. © 1976.