Lymphoproliferative disorder (LPD) is a well recognized complication of solid organ transplantation. It is associated with Epstein-Barr virus (EBV) infection and is often a fatal complication of immunosuppression. We report a 2.5-year-old boy who developed LPD presenting as small bowel lymphoma after liver transplantation. The patient had intermittent fever after transplantation and reactivation of latent EBV infection was documented by pre- and posttransplant serologic tests. About 5 months after his liver transplantation, the patient had sudden onset of abdominal pain and emergency laparotomy was performed for peritonitis. He proved to have multiple small bowel perforations caused by B cell lymphoma and died of multiple organ failure 9 days after operation, despite aggressive treatment and stopping immunosuppressive agents. We conclude that prevention of overimmunosuppression in pediatric recipients after liver transplantation and early detection and treatment of LPD are important to decrease this often-fatal complication.