Eighty patients receiving hematological stem cell transplantation (HCT) with a preparative regimen consisting of total body irradiation (12.5 Gy), cyclophosphamide (4000 or 4500 mg/m2), and thiotepa (400 mg/m2) were evaluated for the development of cardiac toxicity. Patients in whom the pretransplant cumulative dose of anthracycline was more than or equal to 300 mg/m2 showed a lower left ventricular ejection fraction (EF) before HCT compared to patients with less than 300 mg/m2 (0.61 +/- 0.09 vs 0.67 +/- 0.06, P = 0.0010). Patients who had undergone more than or equal to six courses of chemotherapy showed a decreased EF before HCT compared to those after less than six courses (0.67 +/- 0.05 vs 0.63 +/- 0.09, P = 0.03). Three of seven patients (43%) whose pretransplant EF had been less than or equal to 0.55 developed severe cardiac toxicity, characterized by congestive heart failure (CHF) compared with none of 83 patients (0%) whose pretransplant EF had been more than 0.55 (P = 0.00026). Of the three patients who developed severe cardiac toxicity, two were given more than 300 mg/m2 of cumulative anthracycline and underwent 23 courses and six courses of chemotherapy, while the other patient received only two courses of chemotherapy with a total dose of 139 mg/m2 of anthracycline. These results indicate that an increased cumulative dose of anthracycline and number of chemotherapy treatments are correlated with a decrease of the EF and that the EF before HCT is useful for predicting the risk of cardiac complications for recipients who have received chemotherapy.