Preeclampsia is a pregnancy-related hypertensive disease resulting in substantial maternal and neonatal morbidity and mortality. Until today there is no satisfactory treatment to stop disease progression except immediate delivery of the fetus. Heparin-mediated extracorporeal low density lipoprotein (LDL) precipitation (H.E.L.P.) apheresis removes simultaneously circulating LDL, lipoprotein(a) [Lp(a)], fibrinogen, C-reactive protein (CRP) and various proinflammatory and procoagulatory factors. This study was to test the feasibility of H.E.L.P. apheresis in preeclamptic patients and its potential effects on blood and placental markers of preeclampsia. We applied H.E.L.P. apheresis to nine preeclamptic patients and it was well tolerated. Their gestational ages could be continued by 17.7 (3-49) more days. Eight of the nine neonates did well during their neonatal stage. One infant died of late-onset sepsis. H.E.L.P. apheresis reduced significantly circulating levels of triglycerides, total and LDL-cholesterol, Lp(a), fibrinogen, hs-CRP, TNFalpha, sVCAM-1, E-selectin, lipopolysaccharide binding protein (LBP), homocysteine and plasma viscosity. We conclude that H.E.L.P. apheresis reduced maternal circulating levels of proinflammatory and coagulatory markers and plasma viscosity without overt maternal or neonatal clinical side effects.