During the 2-year period 1987 through 1988, 124 patients were assessed for heart or heart-lung transplantation. Sixty were accepted for heart transplantation, of whom 49 received transplants. Nine required pretransplant intra-aortic balloon pump support (+/- positive-pressure ventilation) for periods ranging from 2 to 15 days (mean 5 days). One patient was supported successfully by a pneumatic biventricular assist device for 70 days pretransplant. The 30-day survival in this group of 10 critically unstable patients was 100% and the 6-month survival 90% (one death). This experience compares well with survival rates of 100% at 30 days and 92% at 6 months in the 39 patients who required no form of pretransplant circulatory support. The biventricular assist device also has been used in 2 other patients; one did not survive to transplant and the other was deemed unsuitable by virtue of cerebral injury. Extracorporeal membrane oxygenation supported 2 posttransplant patients (one heart and one heart-lung) with grossly impaired pulmonary function for periods of 5 and 2 days respectively, but both died before lung function had recovered.