With improvements in surgical techniques and management of postoperative complications, heart transplantation can now be performed with donors and recipients who were previously considered unsuitable. In this study, we report the results of heart transplantation with marginal donors and recipients in our hospital. From June 1993 through June 1998, we performed 79 heart transplantations. Marginal recipients were defined as those with high pulmonary vascular resistance (> 6 Wood units), severe renal impairment (serum creatinine > 2 mg/dL and creatinine clearance < 50 mL/min), or severe hepatic dysfunction (ALT and AST > 100 IU/L or serum bilirubin > 2.5 mg/dL). Marginal donors were those with any of the following conditions: old age (> 40 years), size mismatch (donor/recipient body weight ratio < 0.8), history of chronic alcohol use, previous cardiopulmonary resuscitation and hypotension, hepatitis B or C virus positivity, coronary artery disease, high-dose dopamine (> 10 micrograms.kg-1.min-1), or prolonged allograft ischemic time (> 4 hours). Of the 79 transplantations performed, 45 (58%) involved marginal recipients or donors. The 30-day mortality rate was 5%, and the 1-year and 5-year survival rates were 87% and 83%, respectively. The survival rates did not differ significantly between cases involving marginal donors or recipients and those involving nonmarginal donors and recipients. There were 27 marginal recipients (34%), only one of whom died during surgery. Five of six recipients with severe renal impairment needed short-term hemodialysis after transplantation. Recipients with high pulmonary vascular resistance had a higher incidence of early acute rejection (5/10 vs 22/69). Thirty-three (42%) of the patients received transplants from marginal donors, four of whom died during surgery; two died of acute vascular rejection, one of allograft failure caused by prolonged ischemic time, and one of bleeding secondary to preoperative sepsis and coagulopathy. These results show that heart transplantation may be performed in marginal recipients and donors, with acceptable operative mortality.