The reliability of bilirubin analyses is especially important in cases of neonatal hyperbilirubinaemia. However, when the means of the results of external quality control surveys and the method-dependent stated values for control sera were compared with reference method values, differences of up to 10% were found. Further inaccuracy arose from interlaboratory imprecision, which showed coefficients of variation of at least 7%, and from greater or lesser interference from contamination of samples with haemoglobin. The present work investigates whether the current situation can be improved by available means.