Preeclampsia (PE), which occurs in approximately 5% of pregnancies worldwide and constitutes clinically serious complications in 2-3%, is one of the leading causes of maternal and prenatal morbidity and mortality. Recent studies report that regulatory T (Treg) cells, which act as immunosuppressant, are associated with PE. It is clearly defined that FOXP3/Scurfin (Forkhead Box P3) is involved in the development and function of Tregs. However, there are different conclusions regarding the relationship between PE and FOXP3 gene polymorphisms for different populations. For this reason, in this study we investigate the association between FOXP3 gene promoter region polymorphisms and PE in a Turkish population 500 PE patients and 500 healthy pregnant women. Blood samples taken from pregnant women were studied by PCR-RFLP method. As a result, rs2232365 polymorphism was significantly associated with disease (p < .0001) while no significant association was found between rs3761548 polymorphism and the disease (p = .17). Based on these results, it is though that FOXP3 rs2232365 polymorphism may be predisposed to PE development in terms of Turkish population. However, further and functional studies are needed in terms of other polymorphisms and mutations.IMPACT STATEMENT What is already known on this subject? A number of recent publications suggest that Tregs may play a role in the pathogenesis of PE. It is known that a stable and high FOXP3 expression is required to maintain the suppressive T cell function of Tregs. Down regulation of FOXP3 in PE has been reported in many previous studies, but the mechanism is still uncertain. What do the results of this study add? Our study has examined two FOXP3 promoter region polymorphisms in terms of Turkish population for the first time. Rs2232365 polymorphism associated with the disease in heterozygous genotype.