Our broad, long-term goals are to improve outcomes for children who undergo liver transplantation. The primary objectives of the proposed study are to examine functional outcome of these patients on several important levels. First, health-related quality of life (HRQOL) will be measured in a large cohort that has been followed prospectively through the Studies of Pediatric Liver Transplantation (SPLIT) medical outcomes study. SPLIT is an industry-funded consortium of 38 centers established in 1995 to follow medical outcomes not captured by the United Network for Organ Sharing (UNOS) database. The database now includes 1308 children who have received their first liver transplant. Responses from a well-validated, pediatric instrument measuring HRQOL in 800 of these children will be compared to a normative population. Medical variables and demographic information collected before and following transplantation will be used to develop a model, which predicts HRQOL and which could serve as the foundation for intervention studies to improve HRQOL after transplant. Second, a longitudinal study of intellectual ability, school readiness, academic achievement and behavior will be conducted in a sub-set of the cohort defined by age. Approximately, 150 children will be studied at 5-6 years of age and two years later. Testing batteries will include measures of intellectual quotient, reading and arithmetic skills, adaptive behavior (daily-living skills), organizational skills, and screening for abnormal behavior. Specifically, this study will test the hypothesis that functional outcome is lower for children after liver transplant than for normal children. It is expected that HRQOL will improve with interval from transplant, but will not be equal to a normative population. Cognitive development will likewise be delayed and is expected to correlate with age at transplant, acuity of illness and medical complications at the time of transplant and ongoing medical disability. This multi-center collaborative study will be supported by consultants with expertise in outcomes and quality of life research and developmental assessment. It is expected that information gained in this study will allow clinicians to identify interventions that optimize outcomes and better inform patients, families and clinicians about functional expectations for children after liver transplantation.