The use of donor hearts from heart-lung recipients, the so-called domino procedure, began at Papworth Hospital in November 1988. Between then and September 1992, 198 heart transplantations and 86 heart-lung transplantations were performed. Fifty-three heart-lung recipients donated their hearts for use in the domino procedure. Thirty-two domino hearts were transplanted at Papworth and 21 were exported to other centers. Institution of the domino procedure allowed us to perform 19% more heart transplantations (166 to 198) than would have been done had the procedure not been used. The ischemic time was significantly shorter for the domino hearts compared with organs from brain dead donors (134 minutes versus 191 minutes; p < 0.001). No difference was found in the 3-month (84% versus 83%) or 1-year (74% versus 76%) survival between domino and nondomino recipients. Other potential advantages of the domino procedure include detailed pretransplantation evaluation of the heart in live donors and the potential for human leukocyte antigen matching. Additionally many heart-lung recipients have elevated pulmonary artery pressures and a "conditioned", hypertrophied right ventricle. The use of such hearts for heart transplantation has theoretic appeal for patients with elevated pulmonary vascular resistance.