Preeclampsia is a relatively common pregnancy-related condition associated with serious maternal and fetal morbidity and mortality. It is now well established that anti-angiogenic sFlt1 is upregulated in preeclampsia and binds PlGF and VEGF, causing an imbalance in angiogenic factors with subsequent endothelial injury and dysfunction. Measurement of placental growth factor (PlGF) and the sFlt1/PlGF ratio have both been validated in other countries for screening and diagnosis of preeclampsia and the differentiation of preeclampsia from other hypertensive disorders of pregnancy. There are several automated, commercially available immunoassays capable of measuring PlGF and the sFlt1/PlGF ratio for preeclampsia diagnosis. Here we outline the methodology for using the Roche Cobas® e 411 immunoassay platform to determine the sFlt1/PlGF ratio.