Objective: Hypertriglyceridemia is an important pathophysiological feature of pre-eclampsia, a complication associated with retarded fetal growth. We studied the relation between third-trimester maternal triglyceride levels and infant birth weight in 113 pre-eclamptic and 150 normotensive women. Methods: Plasma triglyceride concentrations were determined using enzymatic methods. The relative risk of infant low birth weight (LBW, < 2500 g) was determined using logistic regression to calculate the odds ratio (OR) and 95% confidence interval (CI). Results: Approximately 12% of normotensive and 32% of pre-eclamptic mothers delivered LBW infants. After adjusting for maternal age, parity, pre-pregnancy adiposity and gestational age at delivery, pre-eclamptics were 2.3 times more likely to deliver a LBW infant as compared with normotensive mothers (95% CI 1.1-5.0). There was no association between plasma triglyceride level and infant birth weight. Pearson correlation coefficients for birth weight and triglyceride were r = 0.10 (p = 0.24) and r = 0.06 (p = 0.49) for normotensive and pre-eclamptic women, respectively. The OR for LBW associated with high triglyceride level (≥ 233 mg/dl) was 0.8 (95% CI 0.2-3.1) and 0.9 (95% CI 0.4-2.0) for the two groups. Triglyceride levels did not modify the pre-eclampsia and LBW association. Compared to normotensive women with low triglyceride level (< 233 mg/dl), the ORs for LBW were 1.2 (95% CI 0.4-4.0), 3.6 (95% CI 1.0-12.5) and 2.8 (95% CI 1.0-8.0) for normotensive and high triglyceride, pre-eclamptic and low triglyceride, and pre-eclamptic and high triglyceride mothers, respectively. Conclusions: Hypertriglyceridemia in late pregnancy, considered a maternal adaptation to maintain stable fuel distribution to the fetus, was not related to birth weight.