Long-term leukemia survivors (46) underwent cardiac evaluation, including physical examination, ECG, exercise testing, and echocardiography. They were 2-17 years old at diagnosis and 5-23 years old after treatment. Thirty-four survivors received anthracyclines (AC) (mean 203 mg/m2), 12 of them had also alkylating agents (AA) and 12 had no AC. Exercise tolerance was bellow predicted values in 21 (48%) survivors and 21 survivors had ECG abnormalities, which were more frequent in those treated with AC. Concomitant AC with AA was correlated with prolonged isovolumic relaxation time (IVRT) and influenced significantly the volume of left atrium (p = .02). Sixteen (52%) survivors had IVRT > or = 90 ms. There were no significant differences in other parameters of diastolic or systolic function. Despite the lack of clinical symptoms in the survivors treated with lower doses of AC, subtile abnormalities in myocardial function were found, mainly manifest as abnormal diastolic function. Prolonged IVRT may be a sensitive indicator for early detection of AC cardiotoxicity.