Aim: The aim of this study is to study the levels of cancer antigen 125 (CA-125) in normal, preeclampsia, and gestational hypertension study groups and correlate with other parameters which mark the severity of the disease. Materials and methods: A cross-sectional study was conducted at a Tertiary Care Hospital, Mangaluru, India. A total of 165 subjects were divided into three study groups: preeclampsia, gestational hypertension, and normal pregnancy, and each group consisted of 55 subjects. CA-125 levels were measured in these study groups. Results: The mean value of CA-125 in the preeclampsia group was 56.7 IU/mL which was significantly higher compared with other two study groups. CA-125 was found to have a positive correlation with systolic blood pressure (BP) (r value = 0.4, p value = 0.001), diastolic BP (r value = 0.3, p value = 0.001), and uric acid (r value = 0.2, p value = 0.001) and also an association was observed between increasing CA-125 and proteinuria (p value = 0.001) oligohydramnios (p value = 0.001) fetal growth restriction (p value = 0.03) and onset of the disease (p value = 0.001). However, a negative correlation with platelets (r value = −0.14, p value = 0.06) and birth weight (r value = −0.113, p value = 0.15) was observed. Conclusion: CA-125 is a marker indicating increasing severity of the disease. It is a biochemical marker which can be used in the screening of preeclampsia. Further studies are needed for the evaluation of raising serial CA-125 levels as a marker of progression of the disease. Clinical significance: Hypertensive disorders of pregnancy are one of the most common causes of death due to pregnancy. CA-125 was proposed to be elevated in patients with hypertension due to chronic inflammation. Hence, CA-125 levels if used as a screening tool can estimate the severity of the disease and help clinicians in identifying women who are at risk for further complications and act accordingly.