. To study endothelial function in relation to anti-angiogenic biomarkers and the inflammatory process in preeclampsia. Design. Observational study. Setting. Data were obtained from pregnant women who were admitted to the obstetrical ward at the Karolinska University Hospital, Solna, Stockholm, Sweden. Population. Thirty-five women with newly developed and untreated preeclampsia and 30 healthy controls. Methods. Flow-mediated dilation of the brachial artery, levels of anti-angiogenic and inflammatory markers were measured in plasma during pregnancy and 3–6 months after delivery. Main outcome measures. Flow-mediated dilation of the brachial artery, anti-angiogenic and inflammatory markers. Results. Flow-mediated dilation was decreased in the preeclamptic group at inclusion and at follow-up (p<0.05). Pentraxin 3 (PTX3) and ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) were elevated in women with preeclampsia during pregnancy (p<0.001). Furthermore flow-mediated dilation was lower and the ratio sFlt-1/PlGF and PTX3 were higher in early-onset preeclampsia than late preeclampsia (p=0.018, 0.002 and 0.039). Levels of PTX3 at inclusion correlated inversely with flow-mediated dilation at follow-up both in the preeclampsia and control groups (Spearman, rs=–0.47, p=0.02 and rs=–0.46, p=0.02 respectively). Conclusion. Impaired endothelial function and increased ratio sFlt/PlGF, elevated PTX3 is present in women with preeclampsia and is especially pronounced in women with early-onset preeclampsia.