Epstein-Barr virus-associated lymphoproliferative disease (EBV-LPD) is a serious disorder seen in various states of immunodeficiency, often with a fatal outcome. In this article, a patient with EBV-lymphoma after autologous stem cell rescue for treatment of a nonhematologic solid tumor is described. The child, a 4-year-old boy, had unilateral retinoblastoma with metastatic spread to the central nervous system. He had previously received both local tumor bed and craniospinal radiation therapy together with intensive myeloablative alkylator chemotherapy before autologous stem cell rescue. Histologically confirmed lymphoma with evidence of active EBV proliferation developed within cervical lymph nodes 3 weeks after his first autologous stem cell rescue. A complete clinical remission of the lymphadenopathy was obtained after infusions of rituximab (an anti-CD20 monoclonal antibody), acyclovir, and high-titer anticytomegalovirus immunoglobulin. The patient died approximately 6 months later of persistent and progressive retinoblastoma without any clinical evidence of lymphoma. It is concluded that EBV-LPD should be included in the differential diagnosis in patients in whom lymphadenopathy develops after autologous stem cell rescue.