The present study was designed to evaluate the significance of echocardiography versus cardiac troponin I levels in early detection of anthracycline dependent cardiotoxicity in acute lymphoblastic leukemia (ALL) patients. A total of 276 pediatric ALL patients were included in the study prospectively along 3 phases of data collection lasted from 2002 to 2009; including phase I (March 2002 to February 2003; n = 25; 53.3% females), phase II (September 2003 to April 2004; n = 35; 57.1% females), and phase III (January 2005 to June 2009; n = 216; 52.7% females) with respect to cumulative anthracycline doses applied. Anthracyclinewas administered in accordance with berlin-Franfurt-Munich (BFM)-2000 protocol in doses of 30 to 350 mg/m(2) (in the first phase) and 30 to 240 mg/m(2) (in the following phases). Evaluation of cardiotoxicity was performed via echocardiography and measurement of cardiac troponin I levels. Patients in each phase were homogenous in terms of gender and age. Diastolic dysfunction determined via reduction E/A ratio below the cutoff value was demonstrated to deteriorate earlier than systolic functions and alteration in cardiac enzymes. Being similar between dose groups, cTnI levels were shown to rise in the presence of congestive heart failure. In conclusion, anthracycline cardiotoxicity appears to be detected in an earlier stage by using diastolic parameters compared to systolic parameters and cardiac enzymes.