Purpose: To determine whether there is any association between infant birth weight and maternal serum zinc level. Methods: This case-controlled study vas carried out at the Obstetrics and Gynaecology Department o f the Social Insurance Organisation Hospital (SSK Hospital) in Ankara between July 27 and August 3, J 998. Venous blood samples were obtained from the mothers. Serum zinc level vas determined by the calorimetric method. Twenty women vho had delivered low-birth-weight infants (< 2500 g) were taken as the case group, and from the mothers who had delivered normal birth weight (>2500g) infants, 40 were selected at random as the control group. Results: Mean serum zinc level of women with low-birth-weight infants vas significantly lover than that of their counterparts with normal birth weight infants. Conclusion: The effect of maternal zinc deficiency on fetal development and infant birth weight should be studied in different populations. While evaluating the results of this study, it vas concluded that low maternal serum zinc might be the cause of delivery of low-birth-weight infant.