Cases of severe pregnancy-induced hypertension or eclampsia were studied in forty-five women by catheterization of the right side of the heart to define the presenting hemodynamic profile associated with this disorder. These women could not be easily categorized into one specific hemodynamic pattern. Most patients had high-normal to elevated systemic vascular resistance indices (mean 2726 +/- 120 dynes.sec.cm-5.m2). The mean cardiac index was 4.14 +/- 0.13 L.min-1.m2. The severity of hypertension was largely attributable to a disproportionate rise in the systolic component (mean 193 +/- 3 mm Hg) compared with diastolic blood pressure (mean 110 +/- 3 mm Hg). Women with eclampsia had significantly lower arterial blood pressure and systemic vascular resistance indices when compared with those of the rest of the study group. Analysis of Starling curves indicated that all patients had normal or hyperdynamic left ventricular function. A modest correlation was observed between central venous pressure and pulmonary capillary wedge pressure (r = 0.59). This disparity most likely results from the maintenance of normal to high cardiac output in the presence of an increased left ventricular afterload. The majority of patients with severe pregnancy-induced hypertension do have normal to high cardiac indices and pulmonary capillary wedge pressures accompanied by normal or hyperdynamic left ventricular function. This is true despite the presence of severe hypertension.