Acute renal failure (ARF) is regarded as relatively uncommon in preeclampsia-eclampsia (PE-E) and, in any event, of moderate degree or reversible. Cortical necrosis is reported as rare, even in fatal cases. Little light has as yet been shed on the mechanisms responsible for ARF in PE-E. This paper describes 17 cases observed over the last 15 years, in which cortical necrosis (3 histological and 2 clinical diagnoses) was relatively frequent (29.4%). The severity of renal impairment did not appear to be related to chronological age, parity, period of pregnancy in which PE-E commenced and its duration prior to delivery, presence of frank eclamptic crises or the concomitance of earlier vascular or renal disease (p greater than 0.05). The superimposition of abruptio placentae (AP) was the only clinical factor significantly correlated with cortical necrosis (p greater than 0.05). The association PE-E + AP seems to be a particularly unfavorable prognostic sign for the kidney owing to the contribution of additional damage mechanisms (vasospasm, disseminated intravascular coagulation, hemorrhagic shock) furnished by AP, while PE-E itself prepares the ground for AP. The fact that PE-E is difficult to diagnose when AP is the onset symptom may be responsible for the underestimation of its contribution towards the induction of severe renal damage.