Background: Preeclampsia is a multiorgan disorder and characterized by an imbalance in angiogenic factors, including soluble endoglin (sEng). Till now, the relationship between serum levels of sEng with the severity of preeclampsia is not fully elucidated. The study aimed to clarify the precision of serum soluble endoglin (sEng) in the diagnosis of preeclampsia. Materials and Methods: A casecontrol study has been conducted in the Department of Obstetrics and Gynaecology and clinical biochemistry department, Al-Yarmouk Teaching Hospital, college of medicine/ Mustansiriyah university, Baghdad-Iraq for six months duration. A total of 130 subjects were enrolled. Among them, 40 subjects of non-severe preeclampsia patients (Group 1), 40 of severe preeclampsia (Group 2), and 50 healthy pregnant normotensive women served as controls. Levels were estimated by enzyme-linked immunosorbent assay technique (ELISA) in both cases and controls. Results: There are no significant differences in age among the three groups with a mean age of controls (27.62 ± 4.76), non-severe PE (27.72 ± 5.99), and severe PE (27.90 ± 5.34) years with (p > 0.05). Similarly, no significant differences between non-severe PE and severe PE groups regarding gestational age when compared to the control group (p < 0.691). Mean level of sEng was the highest in severe preeclampsia group (4.04 ± 2.60 ng/mL) as compared to non-severe group (1.63 ± 0.41) and in controls (0.11 ± 0.28) with p-value (p< 0.001). The results showed that the area-under-the-curve (AUC) of serum soluble Endoglin in cases compared with control was (1.00) with a confidence interval (95% CI). The sensitivity and specificity for sEng in PE groups were (100%). On the other hand, compared with the control group, PE groups showed significantly higher creatinine, blood urea, uric acid, ALT, and AST (p < 0.001). Platelet, hemoglobin, PCV, PT, and PTT showed a significant decrease when compared to control at p-value (p = < 0.001) for the first three, (p = 0.001) for PT and low significant for the last (p = 0.03). sEng levels were moderately correlated with platelets (r = 0.312), (p