The feasibility and efficacy of extracorporeal membrane oxygenation (ECMO) as a bridge to cardiac transplantation was examined in 6 pediatric patients who suffered irreversible myocardial failure after undergoing surgery for congenital heart defects. The mean time of ECMO support was 260.5 h, range 101-402 h. Three patients underwent transplantation, 2 of whom are long-term survivors. Progressive hypotension as a result of capillary leak syndrome precluded further ECMO support in the other 3 patients. Overall, 2 of the 6 patients survived. Major complications were encountered in 4 patients including bleeding in 2, a seizure in 1, and renal failure in 3, 2 of whom recovered renal function after transplantation. Infection did not occur in any of the 6 patients. Exchanging ECMO components was performed with no difficulties; these exchanges included a centrifugal pump once for 3 patients and a membrane oxygenator once for 2 patients. Our results indicate that ECMO can safely keep critically ill pediatric transplant candidates alive for more than 1 week with a low incidence of multiple organ failure.