CONTEXT: In Nigeria, hypertension and it’s complications are a major contributor to maternal and prenatal morbidity and mortality. Available evidence implicates deficiency of calcium as a possible cause of Hypertension. Studies done in western countries give conflicting reports on plasma calcium levels in preeclamptic / eclamptics compared to normotensive pregnant controls. Hence there is the need to duplicate such study. OBJECTIVES: To determine if there is a statistically significant difference in plasma level of calcium among preeclamptic/eclamptic compared to parity and gestational age matched normotensive controls and to correlate this with blood pressure levels. DESIGNS: Prospective cross- sectional cohort study SETTING: Department of Obstetrics and Gynaecology, Lagos State University Teaching Hospital, Ikeja, Lagos State. SUBJECTS: Plasma serum calcium level were evaluated in 80 preeclamptic / eclamptic patients and were compared with 80 parity and gestational age matched controls.