Background: Preeclampsia is a common pregnancy-specific disorder associated with significant maternal and fetal morbidity and mortality worldwide. It has been proposed that the imbalance between two CD4+ T cell subtypes, regulatory T cells (Treg) and T-helper 17 cells (Th17), is involved in the pathophysiology of preeclampsia. Objectives: To determine the serum levels of IL-17, IL-21, IL-23 and TGF-β in patients with preeclampsia. Methods: Blood samples were collected from 30 preeclampsia patients, 30 normotensive pregnant women and 30 healthy individuals with no history of malignancies or autoimmune disorders based on simple sampling. The serum levels of IL-17, IL-21, IL-23 and TGF-β were measured by the enzyme linked immunosorbent assay (ELISA). Results: The serum levels of IL-17 and TGF-β were significantly higher in preeclampsia patients compared to normal pregnant group and healthy individuals (p>0.0001) but interestingly, the opposite was the case for IL-23 (p=0.005). However, there were no significant differences in IL-21 between preeclampsia and normal pregnant group. Conclusions: Our results conclude that contrary to IL-21, serum levels of IL-17 and TGF-β significantly increased in preeclampsia compared to normal pregnant women, supporting an imbalance of cytokine profile in preeclamtic patients.