The purpose of the present clinical investigation was to determine the influence of aggressive management, associated medical/obstetric complications, race, and gestational age on fetal, neonatal, and maternal risks associated with severe preeclampsia. Three hundred and three consecutive pregnancies complicated by severe preeclampsia were studied. All patients were delivered within 48 hours after admission to the perinatal center. In 91 patients the disease was superimposed on chronic hypertension. There was a significant difference between patients with and those without prior chronic hypertension regarding perinatal mortality (32 versus 7.7%), incidence of abruptio placentae (10 versus 4%), and frequency of small-for-gestational-age infants (33 versus 14%). Fifty-one patients (17%) had thrombocytopenia, 26 (8.5%) had hemolysis, elevated liver enzymes and low platelet count syndrome, and 22 (7.3%) had disseminated intravascular coagulopathy. There was a significant difference between white and black patients regarding the frequency of thrombocytopenia (28 versus 13%), hemolysis, elevated liver enzymes, and low platelet count syndrome (19.7 versus 5.3%), and coagulopathy (13 versus 1.4%). However, most of this apparent racial difference resulted from higher incidence of abnormal hematologic findings among patients who had conservative management by private physicians before transfer. Perinatal survival was zero when severe preeclampsia developed at or before 28 weeks, whereas it was 100% when disease developed after 36 weeks' gestation. The above factors should be considered in counselling patients with severe preeclampsia.