Background: Pre-eclampsia (PE) is one of the most common medical complications of pregnancy associated with increased maternal and perinatal mortality and morbidity. Its exact etiology is not known, although several evidences indicate that various elements might play an important role in pre-eclampsia. Pre-eclampsia is characterized by vasospasm, elevated blood pressure, and increased neuromuscular irritability, features also common to syndromes of magnesium deficiency. Evidence of serum and ionized magnesium metabolism disturbances have been observed in women with preeclampsia. The identification of an effective strategy to prevent pre-eclampsia is a priority and a challenge for research in obstetric practice. Progress has been hampered by inadequate understanding of the underlying etiology of the disease. The role of maternal diet, particularly magnesium in the etiology of pre-eclampsia has recently received increased attention. Few data exist regarding the serum magnesium levels in pre-eclamptic and normotensive pregnant women in our obstetric population, where most of the morbidity and mortality from pre-eclampsia and eclampsia occur. It is therefore, pertinent to study the levels of serum magnesium in the pre-eclamptic and compare with normotensive pregnant women in Jos. 2 Objective: This study was undertaken to compare the serum magnesium levels in pre-eclamptic and normotensive pregnant women in Jos University Teaching Hospital, Jos, North Central Nigeria. Methods: It was a cross-sectional study conducted from1st May 2011 to 30th April 2012. It comprised of 50 patients and 50 controls. A structured investigator administered questionnaire was administered directly to each subject. For each recruited pre-eclamptic patient (case), the next eligible normotensive patient that matched her for age, occupation, level of education, socioeconomic status, parity and gestational age was recruited as control. Venous blood samples were collected from pre-eclamptic and normotensive pregnant women. The sera samples were analyzed for magnesium, using a photometric colorimetric analyzer (by Diagnosticum Zrt; Budapest). The data were analyzed using the Student's t-test and chi square test.