Abstract Objective Ischemia-modified albumin (IMA)is a modified type of albumin protein that is formed under oxidative stress. This study aims to compare the levels of serum IMA between normotensive and preeclamptic pregnancies and to evaluate the relationship between the severity of the disease. Methods A total of 90 pregnant women aged between 18 and 45 years participated in this cross-sectional study. The levels of serum IMA were measured by enzyme-linked immunosorbent assay in 30 preeclamptic pregnant women with the severe signs of the disease, 30 preeclamptic pregnant women, and 30 normotensive pregnant women.. The study was designed as a cross-sectional clinical study. Results When the demographic characteristics were examined, statistically significant differences were found between the groups in terms of age, gestational week at birth and blood pressure. Age was higher in the preeclampsia with signs of severity group than in the normotensive group (p = 0.033). Pregnancy week was significantly the lowest in the preeclampsia with the severity signs group (p = 0.004). In normotensive patients, IMA levels were lower than in the preeclampsia groups (p = 0.001) but there was no significant difference in terms of severity of disease (p = 0.191). According to laboratory data; only the creatinine level was significantly different between the groups. Conclusion The levels of serum IMA were higher in patients with preeclampsia than in healthy pregnancies. However, there was no significant correlation in terms of preeclampsia severity; more extensive, prospective and long-term studies are needed.