One hundred thirty-six patients underwent radionuclide ventriculography as part of an evaluation prior to bone marrow transplantation. One hundred twenty-six who were considered suitable transplant candidates began conditioning chemotherapy or chemoradiotherapy and were retrospectively evaluated for development of cardiac toxicity. The cumulative pretransplant anthracycline dose in patients who began the conditioning regimen was not a significant predictor for decreased pretransplant ejection fraction (EF) or severe cardiac toxicity following transplantation. Fourteen patients (10%) had EFs less than 50%. Of these, 10 began the preparative regimen and two (20%) experienced grade III or IV cardiac toxicity (95% confidence interval (CI) 2.5-56%) versus five of 116 patients (4%; CI 1.4-9.8%) with EFs greater than or equal to 50% (p = 0.096). The incidence of grade III or IV cardiac toxicity among patients with any history of cardiac dysfunction or with an abnormal physical examination prior to transplant was 9% (two of 22) versus 5% among the remaining patients (five of 104) (p = 0.605). Though transplant-related cardiac toxicity may be more common in patients with mildly reduced EFs, the small number of patients with reduced EFs referred for transplant does not warrant the routine pretransplant screening of all patients with radionuclide ventriculography.