Hypertension is an important cause of both maternal and fetal morbidity and mortality in pregnant women. There are still no definitive guidelines as to when and how patients should be treated, but it is important that appropriate treatment is initiated early in patients at highest risk and they are closely monitored. Hypertension in pregnancy can be a difficult condition to diagnose and treat because of the numerous and differing classification systems that have been used in the past. One classification system, which accounts for the multisystem involvement which can occur in pre-eclampsia and eclampsia, divides hypertension in pregnancy into 3 main groups: pre-eclampsia, gestational hypertension and chronic hypertension. Little benefit to the fetus has been shown from treating gestational and chronic hypertension, but studies in this area have been small and would not have had the power to show a difference in outcome between treated and untreated groups. However, the reduction in morbidity and mortality in the treatment of pre-eclampsia is significant. Therefore, all pregnancies complicated by hypertension require monitoring to detect the possible onset of superimposed pre-eclampsia/eclampsia. Institutions should have a management strategy for those mothers with severe hypertension including a multidisciplinary approach, where the patient is to be monitored and which antihypertensive agents are to be used. It should not be forgotten that the definitive treatment for severe hypertension is delivery of the fetus despite risks to fetal morbidity and mortality. This will reduce blood pressure, but hypertension per se may still persist post partum requiring short term therapy.