Laminin is a large noncollagenous glycoprotein localized in the trophoblast and glomerular basement membrane. We measured laminin levels in maternal serum, umbilical cord serum and amniotic fluid, both from preeclamptic and normal pregnant women, by enzyme immunoassay. The serum laminin levels in the preeclamptic group were significantly (p < 0.05 to p < 0.01) higher than those in the normal pregnant group. It has been suggested that laminin plays an important role in implantation of the placenta during early pregnancy. In this study, the amniotic-fluid laminin level at term was found to be lower than maternal serum laminin. We postulate that laminin may not have an important role in the maintenance of late pregnancy. There was a significant positive correlation between maternal serum laminin levels and serum uric acid levels. There was no significant correlation between maternal serum laminin level and blood pressure, urinary protein concentration, or any other laboratory data. These results suggest that there is damage of glomerular and placental spiral arteries in preeclampsia.