Background Preeclampsia is the most important hypertensive disease complicating human pregnancy in the world. It is a condition of placental origin with adverse effects on the placenta itself, the fetus and the mother. Its pathophysiology is complex and incompletely known. The alterations begin practically from the implantation and continue in the advanced stages of gestation, its maternal-fetal effect is catastrophic. Maternal biomarkers with clinical application have been the subject of extensive research for several decades. The lactic dehydrogenase enzyme and its metabolite L-lactate stand out for their biochemical and clinical importance. In this review, the basic data of preeclampsia are studied, the most interesting evidence from laboratory investigations and the results of the most representative clinical studies are exposed about the role of the lactic dehydrogenase enzyme and L-lactate in normal pregnancy and in the patient with preeclampsia. Keywords: Lactic dehydrogenase enzyme; L-lactate; Lactic acid; Preeclampsia; Eclampsia; Human placenta.