This study develops a capillary electrophoresis/frontal analysis (CE/FA) method to separate free bilirubin from its albumin bound complex, with only small-sized samples. Under our optimized conditions, CE/FA is proven to be a simple and accurate method in assaying the concentration of free bilirubin in the jaundiced serum. Upon saturation of albumin-binding, the amount of bilirubin added to the serum bears a linear relationship with the absorbance at OD44OnM (R = .9987, P < .00001). Application of this method to study jaundiced neonates has yielded precise data on the residual binding capacity, which may be of significant therapeutic implications. The CE/FA method we have developed appears to be promising and applicable for clinical use as it is highly reproducible and it only requires a small sample size for tests. Our method should be an invaluable adjunct to the neonatal management of hyperbilirubinaemia.