In 39 patients with preeclampsia a detailed analysis of some maternal factors, fetal outcome, and a histologic assessment of the presence or absence of acute atherosis in maternal intrauterine vessels has been done. There was no statistically significant relation between acute atherosis and parity, degree of proteinuria, severity and duration of hypertension, or antihypertensive therapy. These findings do not support a purely hemodynamic pathogenesis for the vasculopathy. Fetal outcome was only marginally worse in the preeclamptic patients who developed acute atherosis.