30 serum samples from premature and newborn infants with non-haemolytic hyperbilirubinaemia were analyzed to prove the accuracy of determination of albumin binding capacity for bilirubin. The salicylate method of Odell was used to determine the saturation index of albumin indicated by a decrease in optical density through displaced bilirubin. Bilirubin is stoichometrically displaced from albumin by the addition of salicylate. The values of the sautration index correspond to free binding sites. Analysis of our data demonstrated that there is no direct correlation between the saturation index (SI) and total serum bilirubin/albumin concentration quotient. Methodical errors, problems in statistics and other theoretical concepts are discussed. The salicylate method is not suitable for accurate determination of albumin binding capacity for bilirubin.