Background/Aim. Myocardial cell lesion in newborns may be clinically occult. In recent years there has been shown growing interest in the use of cardiac troponin-I (cTnI) in relation to perinatal asphyxia and hypoxic myocardial lesion. The aim of this study was to determine a relationship between high cTnI levels and outcome in critically ill newborns with perinatal asphyxia. Methods. In this study 78 patients were divided into three groups. The group I included 39 newborns (15 term and 24 preterm) with perinatal asphyxia, with no deaths, only full or partial (with some neurological sequels) recovery. The group II included 10 newborns (6 preterm and 4 term), with perinatal asphyxia who died, with critical cardio-respiratory problems and multiorgan dysfunction. The group III included 29 healthy term newborns. A level of cTnI in all three groups was measured within 24-48 hours after delivery. Results. A statistically significant higher value of cTnI (0.082 μg/l ± 0.166) was found in group I than in the group III (healthy newborns). In the group I, 21/39 newborns required respiratory and 16/39 required pressure support. In the group II, the largest average value of cTnI of 0.425 ± 0.307 was found. All of the newborns in the group II required respiratory and pressure support. In the group III the lowest average value of cTnI (0.0186 μg/L ± 0.0286) was found. Conclusions. High cTnI levels could be used as markers of perinatal asphyxia and even as predictors of future outcomes and/or mortality.