The role of calcium supplementation in pregnancy to prevent preeclampsia is conflicting. The goal was to determine if there was significant difference between plasma calcium levels in women with preeclampsia and normotensive pregnant women. This was a cross-sectional study of 90 consecutive preeclamptic and 90 normotensive pregnant. Blood samples were taken from them and the plasma isolated from each was analyzed using colorimetric method for calcium and albumin employing calcium kit, albumin kit and spectrum lab 7225 spectrophotometer set (Bran Scientific and Instrument Company, England). The data was analysed using SPSS version 16. Their mean ages were 28.67 ± 5.23 and 28.33 ± 5.06 years respectively (preeclamptic vs. normotensive women respectively; P = 0.688). Majority of them were nullipara (48, 53.3% and 46, 51.1% of preeclamptic and normotensive women respectively). The mean gestational age of the preeclamptic women was 36.38 ± 2.54 weeks while that of the normotensive women was 36.24 ± 2.34 years, (P = 0.715). The plasma calcium level in preeclamptic women was significantly lower than in normotensive pregnant women (2.07 ± 0.318 mmol/L vs.2.41 ± 0.224 mmol/L, P \ 0.001). Preeclamptic women have significantly lower plasma calcium levels than normotensive pregnant women in our community. Routine calcium supplementation for pregnant women at risk of developing preeclampsia is therefore recommended.