AbstractEclampsia is frequently associated with brain edema, cerebral infarction or hemorrhage. Its underlying cerebrovascular pathophysiology is still poorly understood. We examined cerebral autoregulation by a non‐invasive multimodal assessment in a 28‐year‐old primaparous woman with postpartal eclampsia. Transcranial Doppler sonography showed considerably increased cerebral blood flow velocity (CBFV) of all basal cerebral vessels. Magnetic resonance imaging demonstrated multifocal vasogenic brain edema. Using transfer function analysis, a severely decreased phase shift between respiratory‐induced 0.1‐Hz oscillations of arterial blood pressure and CBFV was observed, indicating substantial disturbance of dynamic cerebral autoregulation (DCA). In contrast, CO2‐vasomotor reactivity of the right middle cerebral artery was only slightly reduced. We therefore assume that the cerebral arteriolar dysfunction in eclampsia leads primarily to an impairment of the autoregulatory mechanism that is followed by different degrees of arteriolar vasodilation. Because of its probably high sensitivity to hemodynamic disturbances, assessment of DCA might be of great value in early pre‐eclampsia for risk prediction of cerebral arteriopathy and eclampsia. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.