Abstract Background: Soluble suppression of tumorigenicity 2 (sST2), N-terminal pro-brain natriuretic peptide (NT-proBNP), high sensitive troponin I (hs-TnI), and high sensitive troponin T (hs-TnT) are representative cardiac biomarkers. The reference intervals (RIs) of these biomarkers have been rarely investigated in umbilical cord blood (UCB). We explored the distribution of these cardiac markers and established their RIs in UCB. Methods: In a total of 293 UCB specimens, sST2, NT-proBNP, hs-TnI, and hs-TnT concentrations were analyzed according to the gestational age, presence of premature membrane rupture (PROM), presence of gestational diabetes mellitus (GDM), and Apgar score at 1 min. Their RIs were defined in 133 UCB specimens from healthy, full-term neonates, using non-parametric percentile methods according to the Clinical and Laboratory Standards Institute guideline (EP28-A3C). Results: The concentrations of four cardiac markers in UCB were different between full-term neonates and pre-term neonates. The concentrations of NT-proBNP and hs-TnI differed according to the presence or absence of PROM. Their concentrations did not differ regardless of the presence of GDM. The concentrations of sST2 and NT-proBNP differed according to the Apgar score at 1 min. The 97.5th percentile upper reference limits were: sST2, 59.9 ng/mL; NT pro-BNP, 1415.3 pg/mL; hs-TnI, 27.8 pg/mL; and hs-TnT, 86.5 pg/mL. Conclusions: The distribution of sST2, NT pro-BNP, hs-TnI, and hs-TnT in UCB together with their RIs would provide fundamental data for future researches and clinical practice.