Preeclampsia is a heterogeneous pregnancy-specific syndrome associated with abnormal trophoblast invasion and endothelial dysfunction. Magnesium (Mg2+) level is decreased in women with preeclampsia. The use of Mg2+ salts, such as Mg2+ sulphate, are useful in reducing the pathophysiological consequences of severe preeclampsia and eclampsia. Although the mechanism of action of this Mg2+ salt is not well understood, the available evidence suggests a beneficial effect of Mg2+ for the mother and foetus. The mechanisms include lower level of soluble fms-like tyrosine kinase 1 and endoglin, blockage of brain NMDA receptors, decreased inflammation mediators, activation of nitric oxide synthases, blockage of arginases, and reduced free radicals level. The maintenance of Mg2+ homeostasis in pregnancy is crucial for an appropriate pregnancy progression. Oral Mg2+ salts can be used for this purpose thus preventing preeclampsia or mitigating its deleterious consequences to the mother, foetus, and newborn.32