OBJECTIVES: To assess the relationship of patient, payer, and hospital characteristics with cost and mortality in pediatric heart transplant recipients. METHODS: Data from the 1997, 2000, 2003, and 2006 Agency for Healthcare Research and Quality (AHRQ) Healthcare Cost and Utilization Project (HCUP) Kids’ Inpatient Database (KID) were utilized.  Pediatric patients aged 0-17 years receiving heart transplants were included.  Logistic regression and generalized linear models were used for the analyses. Inpatient mortality and inflation-adjusted costs were the outcomes of interest.  Patient demographics and clinical characteristics were the primary independent variables of interest, with payer and hospital characteristics used as control variables. Weighting procedures were utilized to yield nationally representative results.    RESULTS: Overall, 1154 patients received heart transplants during the study timeframe.  The average was 6.5 (±6.1) years.  Mean inpatient hospital costs were $206,895 (±150,504).  Inpatient mortality was 7.2%.  Children >1 year were significantly less likely to die during hospitalization than those <1 year (p<0.05).  Hemorrhage (OR=4.11, p=0.005) and renal failure (OR=6.45, p=0.001) were complications associated with mortality.  Mortality was also significantly associated with higher number diagnoses and higher income and inversely related with West region and more recent transplants.  Mortality cases incurred 1.68 times higher costs than those routinely discharged (p<0.001).  Sepsis (exp(b)=1.18, p=0.04), respiratory disease (exp(b)=1.08, p=0.021), hemorrhage (exp(b)=1.22, p<0.001) and renal failure (exp(b)=1.15, p=0.003) were complications associated with higher costs.  Higher costs were also significantly associated with medium hospital bedsize, age >1 year, admission from another facility, longer lengths of stay, West region, more recent transplants and higher patient income, with lower costs for transplants occurring in a children’s unit of a general hospital.  CONCLUSIONS: Multiple patient and hospital characteristics appear to significantly predict inpatient mortality and costs in pediatric heart transplant recipients.