Many studies have developed nutritional indicators for purposes of predicting maternal outcomes. Mid upper arm circumference (MUAC) as an indicator is beginning to gain attention. The study was designed to assess the use of MUAC for monitoring of pregnancy and identifying women at risk of having low birth weight. The study was carried out in middle-lower socio-economic population in Bogor, West Java. Data was collected each month from identification until delivemy and neonatal data was collected at birth. The study reveals that MUAC was relatively stable during pregnancy, and its measurement is independent ofgestational age. Therefore, MUAC may not be useful as a monitoring tool. On the other hand, the median curve of MUAC during pregnancy for the women delivering adequate birth weight infants (>= 2500 g) was consistently above the curve of the women delivering low birth weight infants (< 2500 g). In addition MUAC had a significant associated with low birth weight (LBW). Accordingly, MUAC appeared to be a potential tool for screening high risk women delivering low birth weight infants. After adjusting with height, the OR was 1.73 for arm circumference of 22.5 cm, and OR was 1.84 for arm circumference of23.7 cm. Infield application, for screening purposes one of these cut offpoints can be used either 22.5 cm or 23.7 cm. In population with high rate of malnutrition, a lower cut offpoint should be taken, otherwise too many women identified as high risk, and this is impractical for program development.