Background: The mechanism involved in the pathogenesis of preeclampsia (PE) remains uncertain, and the research into a better understanding, its possible prediction, and subsequent prevention continues. Aim: This study evaluated changes in serum immunoglobulins (IgG, IgA, and IgM), C-reactive protein, and trace elements (Zn, Cu, and Mn) in preeclamptic, normotensive pregnant, and non-pregnant females. Subjects and Methods: The study was conducted among 150 subjects consisting of 50 preeclamptic subjects, 50 healthy normotensive pregnant women in their third trimester, and 50 non-pregnant women, all within the same age bracket. The serum concentration of the immunoglobulins and C-reactive protein were measured using standard immunoturbidimetric methods, whereas the trace elements were assayed using the atomic absorption spectrophotometric method. Results: Serum IgG and IgM levels were observed to be significantly lower (P < 0.05) in preeclamptic subjects (101.22 ± 4.44 and 769.43 ± 1.43 mg/dl), respectively, when compared to the normotensive pregnant women (123.87 ± 1.81 and 881.71 ± 2.80 mg/dl), respectively. There was a non-significant difference in immunoglobulin A levels between the groups (P > 0.05). The C-reactive protein was significantly higher, whereas the trace elements were significantly lower (P < 0.05) in preeclamptic subjects compared to the normotensives. There was a positive correlation between the immunoglobulin G and Zn levels (r = 0.334; P = 0.046) and also between immunoglobulin G and C-reactive protein levels (r = 0.340; P = 0.043) and a negative correlation between systolic blood pressure and manganese levels in preeclamptic subjects (r = −0.375; P = 0.024). Conclusion: This study therefore reveals significantly lower levels of immunoglobulins and trace elements among the preeclamptic subjects. These micronutrient deficiencies and low levels of immunoglobulins could be risk factors for the development of high blood pressure and PE.