Background: Calcium deficiency is common in pregnant women and newborn infants. There are few data about the prevalence of calcium deficiency during pregnancy and infancy in Algeria. We assessed calcium status of pregnant women and their neonates in Sidi Bel Abbes, west of Algeria. The current study aimed to determine the prevalence of hypocalcemia in pregnancy and in their new born and to correlate maternal calcium status with neonates’ calcium and birth weight. Methods: A prospective study was conducted during five months (January to May 2014), on a representative sample of 900 pregnant women (in the third trimesters) attending MCH center in sidi bel abbes region, west of Algeria. Maternal serum and birth serum calcium, birth weight were studied in 900 mother-neonate pairs. Results: The prevalence of hypocalcaemia in pregnant women was 70.55%. It is noted that 43% (or 387) are premature, 1% cases macrosomia and 79% (504) new-born at term. The results of the study showed that 53.71% of the new born were hypocalcemic, most of these being neonates below 2500 g weight and 41.94% whose weight was between 2500 and 4000 g. The frequency of hypocalcaemia in new born whose mothers were delivered by caesarean sections was 55.94%. The frequency rate of hypocalcaemia in preterm infants was 79.09%. The proportion of hypocalcaemia in new born is higher in age between 0-3 day (46.07%) against 16.33% for age groups 4-7day (p<0.05). Our results noted that gestational diabetes, hypertension (gestational and chronic) and prematurity constitute risk factors for the fetal hypocalcaemia. A frank correlation is noted between the maternal serum calcium and serum calcium levels of the newborn (R= 0.34). A low correlation between the calcium of the newborn and its weight (R= 0.10). By contrast, no correlation was noted between the weight of the new-born and the maternal serum calcium (R=- 0.067). Conclusions: The nutrition of pregnant women does not cover the daily requirements for calcium. It is desirable that the maternity hospitals have dieticians to inform mothers about the benefits of a balanced diet on their health and that of the child. Supplementation is needed to improve maternal and neonatal calcium nutrition.