Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication that may follow orthotopic liver transplantation (OLT) in children. The first symptoms are often in the ear, nose, or throat (ENT) area. This abnormal proliferation of lymphoid cells is related to Epstein-Barr virus (EBV) infection in immunocompromised children. The incidence of PTLD, EBV status before OLT and at the diagnosis of PTLD, delay between OLT and PTLD, localization, pathological investigations, and the treatment and evolution of PTLD were prospectively evaluated in 77 pediatric liver transplant recipients. Eight patients (10%) developed PTLD, all with an ENT presentation. Seven had acute nonbacterial tonsillitis (with a negative throat swab), and 1 had a pharyngolaryngeal localization at the time of the diagnosis. Four patients had associated involvement outside the ENT area. All patients were EBV-seronegative at the time of OLT; 6 underwent seroconversion at the time of diagnosis, and 2 within 9 and 20 months of diagnosis. All patients presented with low-grade PTLD. All patients with acute tonsillitis associated with EBV seroconversion underwent immediate tonsillectomy, and immunosuppression was decreased as much as tolerated. This therapeutic protocol led to complete recovery in all patients. After OLT in children, nonbacterial tonsillar inflammation or hypertrophy associated with an EBV infection is often the first manifestation of PTLD. Tonsillectomy combined with tapering of immunosuppression offers the best chance for a complete recovery.