Eclampsia is a major cause of maternal mortality and morbidity worldwide. Magnesium sulfate is considered the cornerstone for the prevention and treatment of eclamptic seizures. However, the exact dose and the indications for administration remain controversial. Our objective is to describe risk factors, symptoms, and time of onset of eclampsia, as well as to summarize randomized trials dealing with indications for magnesium sulfate and duration of its administration, particularly as it plays to its indications in the postpartum period.