Objectives: Dyslipidemia is thought to be of etiological importance in preeclampsia. We studied the relationship between maternal plasma lipid concentrations and risk of preeclampsia. Methods: A total of 125 preeclampsia cases and 179 normotensive control subjects were included in this case-control study conducted in Lima, Peru, between August 1997 and January 1998. Post-diagnosis, antepartum plasma lipid profiles were determined by standard enzymatic methods. Logistic regression procedures were used to calculate odds ratios (OR) adjusted for potential confounders. Results: Mean plasma total cholesterol and triglyceride concentrations were, on average, 6% and 21% higher in preeclamptics than controls, respectively. High-density lipoprotein (HDL) cholesterol concentrations were, on average, 9% lower in cases than controls. After adjusting for maternal age, pre-pregnancy body mass index, education, parity and other potential confounders, the risk of preeclampsia increased with successively higher quartiles of plasma triglyceride (adjusted OR: 1.00, 1.62, 2.21, 5.00, with the lowest quartile as referent; P-value for trend <0.001). The association between preeclampsia risk and plasma total cholesterol was much less pronounced. In general, there was an inverse association between preeclampsia risk and HDL cholesterol concentration (adjusted OR: 1.00, 0.41, 0.50, 0.38, with the first quartile as the referent group; P-value for trend =0.02). Conclusions: These findings suggest that high triglyceride and low HDL cholesterol concentrations are important risk factors for preeclampsia among Peruvian women. Copyright (C) 1999 International Federation of Gynecology and Obstetrics.