This study examined the role of women's work as a possible determinant (among others) of low birth weight in the population of women followed in a Primary Health Care (PHC) center in Abha, Southern Saudi Arabia. All antenatal care files for all deliveries in the preceding 5 years were studied and the relevant data from 7067 files were collected and analyzed. Low birth weight was significantly higher in working mothers (odds ratio=1.31), adolescent mothers (odds ratio= 2.56), and low parity mothers (OR= 1.28). Anemia of the mother contributed an odds ratio of 1.23 for low birth weight baby and inadequate antenatal care (less than 3 visits during pregnancy) had an odds ratio of 1.9. Female babies were significantly more prone to low birth weight (odds ratio 1.34). It is suggested that further evaluation of women's work conditions to detect and remedy stressful conditions especially during pregnancies, health education and better antenatal care may prevent a good proportion of low birth weight deliveries.