Preeclampsia is a serious pregnancy complication associated with elevated antiangiogenic markers and endothelial dysfunction. Recently nicotinamide (vitamin B3) was shown to reduce high blood pressure and proteinuria in mice models of the disease. Using primary human pregnancy tissue we show nicotinamide did not change antiangiogenic factor secretion including soluble fms-like tyrosine kinase 1 or soluble endoglin from primary cytotrophoblasts and placental explants. Furthermore, it did not reverse markers of endothelial dysfunction. Therefore, we did not demonstrate an effect of nicotinamide on reducing markers of preeclampsia from primary human placental tissues and vascular cells.