In this article, data from the annual international Extracorporeal Life Support Organization (ELSO) Registry Reports through July 2004 are presented. Nearly 29,000 patients have received extracorporeal life support (ECLS). Of the patients, 66% (more than 19,000) were neonatal respiratory failure, with a 77% overall survival to discharge or transfer. The number of neonatal respiratory cases reported to the Registry has decreased from a peak of 1,500 patients in 1992 and has leveled off at approximately 800 cases per year. The number of pediatric respiratory cases has remained at approximately 200 cases per year since 1993, with a 56% survival to discharge or transfer. Adult respiratory failure continues to be the smallest age group treated with extracorporeal membrane oxygenation (ECMO), with less than 100 cases per year. Survival to discharge, however, is comparable with pediatric respiratory failure (53%). Support continues to increase for cardiac failure across all age groups, with survival to discharge rates of 38%, 43%, and 33% for neonatal, pediatric, and adults, respectively. Survival in pediatric and adult respiratory failure cases supported with ECLS has remained fairly consistent over the past 5 years.