Long‐term administration of Intralipid to infants raises the potential risk of cumulative hyperlipemia. The elimination of lipoproteins from the blood during 3 hours of Intralipid infusion (0.33 grams per kilogram per hour) was investigated in five term infants during two infusion periods without and with heparin. A single intravenous injection of heparin (100 micron per kilogram) preceded the period of Intralipid infusion. During the nonheparin periods levels of triglycerides (L‐particles) rose progressively to 1320±133 milligrams per 100 milliliters plasma, whereas during the heparin periods levels rose more moderately and peaked at 636±107 milligrams per 100 milliliter plasma (p<0.001–0.05). The study suggests that the heparin effect is still apparent for a period of 6 hours and repeated bolus injections may keep triglyceride levels at approximately normal concentrations during constant Intralipid infusion (0.166 grams per kilograms per hour).