Perioperative acute donor heart failure can be caused by various factors, such as recipient pulmonary hypertension, marginal donor heart function, or immunologic mismatch. Of 265 patients who underwent orthotopic transplantation, four received mechanical support for acute perioperative donor heart failure. In two patients with reactive pulmonary hypertension, right heart bypass (RHB) with a centrifugal pump was used for 53 and 36 hr, respectively. One patient who experienced biventricular donor heart failure was supported for three days with an intraarterial, transvalvular, axial-flow left ventricular assist device (LVAD). Circulation was supported effectively with the LVAD, despite an initial absence of right ventricular function. The fourth patient, who had signs of heart failure, received intraaortic balloon pump support for 24 hr after transplantation. All four patients were weaned from circulatory support, and heart function was restored in each; the mean left ventricular ejection fraction was 63% (range from 57 to 71%). One patient died of fungal infection 14 days after being weaned from pump support, another died of lymphoma two months after support was discontinued, and the remaining two patients are well 9 and 18 months after transplantation. In cases of acute donor heart dysfunction, temporary mechanical assistance is a reliable option for supporting the circulation during heart recovery.