Background. To determine the plasma concentrations of placental growth factor (PLGF), vascular endothelial growth factor (VEGF), transforming growth factor-β1] (TGF-β1), soluble tumor necrosis factor α receptor (sTNFp55), interleukin-2 receptor (IL-2R), and interleukins 6 and 10 (IL-6, IL-10) in normotensive and preeclamptic women, and to evaluate the correlations between these cytokines and the diastolic blood pressure and fibronectin levels. Methods. A prospective case-control study. Thirty-five women with preeclampsia were compared with 34 healthy women with uncomplicated pregnancies. Peripheral venous blood samples were obtained and plasma levels of PLGF, VEGF, TGF-β1, sTNFp55, IL-2R, IL-6 and IL-10 were measured by an enzyme-linked immunoassay and fibronectin by a radial immundiffusion technic. Results. In preeclampsia PLGF and VEGF levels were significantly lower, and TGF-β1, sTNFp55, IL-2R, IL-6 and IL-10 levels were significantly higher than in normotensive pregnancy (p < 0.001). The plasma levels of PLGF and VEGF significantly decreased, whereas TGF-β1, sTNFp55, IL-2R, IL-6 and IL-10 levels significantly increased with the increments in diastolic blood pressure and fibronectin levels (p < 0.001). Conclusions. Altered concentrations of various cytokines might explain the shallow placentation and endothelial cell dysfunction described in preeclampsia. The clinical severity of preeclampsia seems to correlate with the severity of the cytokine abnormalities.