Aim- To compare the magnesium levels between preeclampsia and control groups from the early stages of pregnancy. Materials and methods- The research population consisted of 200 pregnant women at 18-22 weeks of gestation, with 50 participants divided into clinical (N=20) and control (N=30) groups using purposive sampling. Data analysis was performed using SPSS software. Results- The serum magnesium in preeclampsia pregnant women was significantly less than the control group that consisted of normal pregnant women. Conclusion- Our study revealed a progressive decline in the average serum magnesium levels as the gestational period advanced in women with preeclampsia.