Objective: The aim of the study was to assess myocardial damage in infants due to perinatal hypoxia. Methods: The findings of 29 infants with perinatal hypoxia and 20 healthy infants were compared. Blood gas analysis, serum lactate, cardiac troponin I (cTnI), troponin T (cTnT), creatine kinase-MB (CK-MB) and B-type natriuretic peptide (BNP) were evaluated. Echocardiography together with tissue Doppler imaging was performed. Results: cTnT, CK-MB and BNP were higher in patients at the first day. There were positive correlations between the left ventricular (LV) myocardial performance index (MPI) and cTnT at first day and also at first month. LV ejection fraction and fractional shortening were lower at first day and at first month in patients. Myocardial systolic (Sm) and diastolic (Em and Am) velocities at all segments were lower at first day, and interventricular septum Sm, LV Sm, LV Em, right ventricular Em and LV Am were still lower at first month in patients. Isovolumic relaxation time at all segments together with LV MPI was higher at first day, ejection time values were lower and MPI values were higher at all segments at first month in patients. Conclusions: These findings demonstrated that the signs of myocardial damage due to perinatal hypoxia still present at first month. © 2012 Informa UK, Ltd.