Abstract. OBJECTIVE: To determine the prevalence of high TG levels in extremely low birth weight (ELBW) infants and what the risk factors are for high TG levels. STUDY DESIGN: We performed a prospective observational study of triglyceride concentrations in extremely low birth weight infants receiving lipid infusions. Lipid infusions were begun at 0.5 grams/kg/day at age one day and the dose advanced by 0.5 grams/kg/day. Triglyceride concentrations were drawn when the dose reached 1 and 2 grams/kg/day. We compared infants with normal triglyceride levels (≤200 mg/dl) with those with elevated triglyceride levels (>200 mg/dl) with univariate and multivariate analysis. RESULTS: There were 75 infants included in the analysis. Twenty (26.7% , 95% CI = 16.6–36.7%) had triglyceride levels >200 mg/dl. On multiple logistic regression analysis, lower birth weight was associated with the risk of an elevated triglyceride level. Triglyceride levels >200 mg/dl did not predict future mortality or morbidity. CONCLUSION: Elevated TG levels occur commonly in ELBW infants and are associated with a lower birth weight.