Pre-eclampsia is mainly responsible for the world's large maternal mortality rates, mostly due to acute cerebral complications. This review provides insight into the pathogenesis of the neurologic complications of hypertensive disease in pregnancy. In addition, practical relevance for clinical care is highlighted. Pertaining to pregnancy, the blood pressure level at which cerebral autoregulation operates and possible deregulation occurs is unknown, but is likely to be variable. From clinical observation, eclampsia may occur despite a mild clinical picture and before the development of hypertension or proteinuria. Furthermore, failure of cerebrovascular autoregulatory mechanisms in response to either an acute and/or relatively large blood pressure increase may be more important than the absolute blood pressure value. It may be the acuity of the blood pressure rise in the setting of endothelial dysfunction that interrupts the delicate balance between capillary and cellular perfusion pressures that leads to the neurological complications of pre-eclampsia.