Oleic and palmitic acids at concentrations above 1.1 mg percent (40 micrometer) are capable of displacing bilirubin from the serum albumin-bilirubin conjugates. The release of bilirubin is also demonstrated by thin layer gel chromatography. Since both oleate and palmitate constitute the major fatty acids in breast milk, the results may indicate that the development of jaundice in breast-fed infants could result at least in part from elevated levels of free fatty acids present in the blood serum of these neonates.