This study was undertaken to evaluate the effect of preeclampsia on maternal and cord blood clotting parameters. Pregnant controls and preeclamptics plus their offspring had plasma analyzed for prothrombin time, partial thromboplastin time, fibrinogen, and clotting activity for factors II, V, VII, VIII, IX, X, XII, plus factor II antigen. Maternal data was consistent with that previously reported by numerous authors. The cord blood data showed that neonates of the preeclamptic mother had elevated fibrinogen and decreased II, V and VII activity, plus decreased II antigen. The data indicates that abnormal clotting parameters seen in the neonates from preeclampic mothers may result from impaired liver function and not as previously thought, from a deficiency in neonatal vitamin K.