Placental angiogenesis is critical to the success of human pregnancy. Angiogenesis is defined as the formation of new blood vessels from existing vasculature. Angiogenesis is necessary for the establishment of adequate placental perfusion, which is important for providing the optimum in utero environment to support fetal development. Defective placental angiogenesis is associated with several pregnancy complications, the most clinically important of which is preeclampsia; the multisystem disorder is characterized by maternal hypertension, proteinuria, and endothelial dysfunction. Here, we review our current understanding of several key angiogenic factors that are associated with placental angiogenesis. We also discuss their importance with respect to preeclampsia, where aberrant expression and release of these factors into the maternal circulation is thought to contribute to the pathogenesis and pathophysiology of preeclampsia.