Introduction: Preeclampsia (PE) is a multi-system disorder of pregnancy characterized by hypertension and proteinuria. Healthy pregnancy is associated with a controlled inflammatory process, which is exacerbated in PE in response to excessive placental stimuli. Gene expression levels can affect inflammation and immune regulation. It is known that differences in cytokine allele frequencies amongst populations may contribute to difference in the incidence of several diseases. Objective: The aim of this study was to investigate the frequency of TNF-α, IL-6, IFN-γ and IL-10 genes polymorphisms and their relationship with the cytokines plasma levels in PE. Methods: A total of 281 women were included in this study; 116 with severe PE, 107 normotensive pregnant and 58 non-pregnant women. Cytokine genotyping was carried out by the polymerase chain reaction. The analyzed polymorphisms were: TNF-α (−308 G → A), IL-10 (−1082 G → A), IL-6 (−174 G → C), and IFN-γ (+874 A → T). Cytokine plasma levels were measured by Cytometric Bead Array method. Results: A higher frequency of the IFN-γ (+874) T/T genotype in severe PE comparing to normotensive pregnant women was found (P < 0.001). TNF-α, IL-6 and IFN-γ plasma levels were higher in PE women compared to non-pregnant women (P < 0.001; P < 0.001; P = 0.004). IL-6 and IFN-γ levels were also higher in PE women compared to normotensive pregnant (P < 0.001; P = 0.010). IL-10 levels were higher in normotensive pregnant women compared to PE (P < 0.001). IFN-γ and IL-6 genes polymorphisms influenced the genic expression in PE and normotensive pregnant women, respectively. Conclusions: These results suggest that IFN-γ seems to play a role in PE occurrence.