Introduction: Pregnancy is a period that is characterised by remarkable physiological changes which are needed to support the growing fetus. Micronutrients play a crucial role in the maintenance of pregnancy. Among the micronutrients, magnesium has got ample amount of clinical relevance to pregnancy. Magnesium deficiency has been associated with reproductive risk during pregnancy such as anaemia, pre-eclampsia, eclampsia, fetal growth retardation, preterm labour, low intrauterine growth rate and leg cramps. Aim: To find out whether there was significant difference in the magnesium levels among pregnant women with and without pregnancy related complications and also to find out whether the magnesium levels differed significantly among the three trimesters. Materials and Methods: This was a cross-sectional study done among 240 pregnant patients from different trimesters attending the Obstetrics and Gynaecology Outpatient Department. Out of them 164 women had complications like pre-eclampsia, Gestational Diabetes Mellitus, leg cramps and history of abortions. Demographic details were obtained from all the women. BMI was calculated for each subject using the formula BMI=weight(kg)/height(m2). Haemoglobin was assessed in all samples using cyanmethaemoglobin method. Magnesium levels were analysed in the all samples using automated analyser in the Biochemistry laboratory. Student’s t-test was used to compare the levels of magnesium among the groups with and without complications. ANOVA test was used to compare the three trimesters. Results: The pregnant women were divided into three groups based on the different trimesters in which the samples were taken. Magnesium levels among the women in the first trimester were (2.96±0.83) second trimester (2.99±1.48) and third trimester (3.05±1.48) respectively. Women with previous abortions were found to have less magnesium levels (2.71) compared to women without a history of abortion (3.11) and value was found to be statistically significant (p<0.007) and magnesium levels among vegetarians (2.45) were lower than non vegetarians (3.08) and it was found to be statistical significant (p<0.013). There was no significant difference in the magnesium levels among pregnant women with complications and those without complications. Conclusion: The study shows the importance of maintaining the magnesium levels among pregnant women. There was no difference in the magnesium levels among the three trimesters. Study also points out the influence of parity, diet and occupation of pregnant women on the levels of magnesium.