Aim: Due to the potential toxicity of high concentrations of bilirubin, newborns are monitored in terms of the potential emergence of a group at risk of the development of severe hyperbilirubinaemia and, rarely, encephalopathy and kernicterus. The transcutaneous measurement of bilirubin, as a non-invasive method, is applied in neonatal centres. The paper presents an evaluation of the correlation between the transcutaneous measurement and the concentration of bilirubin in the blood serum of a newborn, taking into consideration the reduction of the necessity to carry out blood tests related to the transcutaneous measurement. Material and method: The analysis comprised 1,076 medical histories of newborns hospitalised at the Department of Neonatology of the Municipal Hospital in Zabrze in the period from 1 January to 31 December 2013 (a primary referral centre). The inclusion criteria for the study were: performing a simultaneous transcutaneous measurement and a blood serum concentration measurement of bilirubin, gestational age ≥35 Hbd and birth weight >2,500 g. 272 children were qualified for the study. Results: Boys constituted 51.7%, and girls 48.3% of the research group. The mean gestational age was 38.7 Hbd and the mean birth weight was 3,323.4 g; 67.8% of the children were born by natural labour and 32.2% – by caesarean section. The mean Apgar score in the 5th minute was 9.8 points. The measurement of the concentration of bilirubin was performed on average on the 3.9 day of life. The mean transcutaneous measurement was 9.67 mg% (2.7–17.2 mg%) and the mean concentration of bilirubin in the blood serum was 13.18 mg% (7.0–19.8 mg%); the difference was 3.5 mg% (p < 0.0001). A statistically significant positive correlation was found between the concentrations of bilirubin obtained in the transcutaneous measurement and the concentrations in the blood serum (according to Spearman, r = 0.58; p < 0.01). Conclusion: It seems that the standardisation of the relationship between the concentration of bilirubin in the transcutaneous measurement and the evaluation of the concentration in the blood serum may significantly affect the reduction of the necessity to perform punctures, the limiting of the child’s stress and pain, the reduction of the risks of infection and it may be of high economic importance.