The resources that are directed towards the care of liver transplant recipients are substantial. Approximately 100 million dollars are spent on the hospitalization of the 400-500 children in the United States who undergo liver transplantation each year. Using length of stay as a surrogate marker for hospital resource use, we sought to identify factors that impact length of stay and assess the trends of hospitalization after liver transplantation for a representative population of pediatric liver transplant recipients. The study population was comprised of 956 patients who underwent primary liver transplantation between 1995 and 2003 and survived at least 90 days. Data were retrieved from the Studies of Pediatric Liver Transplantation data registry. The primary outcome was the length of initial hospitalization after liver transplantation. Independent variables were age, gender, race, pediatric end-stage liver disease score (PELD), year of transplantation, organ type, primary disease, length of operation, and insurance status. The mean and standard deviation of length of stay after liver transplantation was 24.0 +/- 24.5 days. Multivariate analyses showed that increased hospital stay was associated with infants less than 1 year of age, fulminant liver failure, receiving a technical variant organ from a cadaveric donor, government insurance, and transplant era (before 1999 vs. 1999 or later). Decreasing height z-scores and increasing length of operation were also associated with increased hospital stay. In conclusion, these parameters accounted for only 11% of the total variance, suggesting that post-transplant complications and course account for much of the variability of resource use in the immediate post-transplant period.