OBJECTIVES:: Pediatric obesity has become a significant public health concern. The historical focus in pediatric liver transplant (LT) has been undernutrition, with limited knowledge regarding obesity. Therefore, we sought to determine the prevalence of obesity in pediatric LT, compare it to National Health and Nutrition Examination Surveys (NHANES) data, and identify risk factors for obesity in pediatric LT. METHODS:: SPLIT, which collects pediatric LT data at 39 centers, was queried for subjects ages 2 to 18 years at follow-up, LT between 1995 and 2007, and with at least 1 body mass index measured 1 to 5 years after LT. RESULTS:: Of 1706 individuals included, 44% had biliary atresia (47% boys, 58% white, mean age at LT 4.6 years). Of these individuals, 19% were obese at 1 year and 18% at 3 years, higher than in the general pediatric population reported by 2003-2004 NHANES, whereas 11% obesity at 5 years after LT was similar to NHANES data. Using logistic regression, Hispanic ethnicity (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.19-2.23), steroid use at follow-up (OR 1.48, 95% CI 1.23-1.77), overweight (OR 4.34, 95% CI 2.91-6.68), and obesity (OR 10.62, 95% CI 5.9-19.65) at LT independently predicted post-LT obesity. CONCLUSIONS:: These findings suggest a need to broaden standard care to include obesity assessment and intervention in routine pre- and posttransplant care.