Aim: The purpose of this study is to evaluate echocardiographically determined cardiac functions with serum levels of brain natriuretic peptide (BNP), cardiac troponin I (cTnI) and total antioxidant status (TAOS) in childhood leukemia treated with chemotherapeutics containing anthracyclines.,Methods: A study group of 29 patients who have been followed for acute lymphoblastic leukemia (ALL) and administered a treatment protocol containing chemotherapy of anthracyclines were included in the analysis. Levels of BNP, cTnI and TAOS were studied in serum samples of the patients.,Results: We demonstrated that as the drug dosage increased, systolic ejection fraction (EF) and shortening fraction (FS) values decreased (EF r(2) = 0.2327, FS r(2) = 0.251). On the other hand, increased dosage of anthracycline therapy was associated with significant raise in plasma BNP levels (r(2) = 0.246) and significant decrease in serum TAOS levels (r(2) = 0.317) without any change in serum cTnI levels.,Conclusion: Our study suggest that serum TAOS and BNP levels may be useful as an early and sensitive indicator of anthracycline induced cardiotoxicity.