The incidence of malignancy following solid organ and stem cell transplantation is now approaching 30% at 20 years and is related to the degree and duration of immunosuppression as well as viral cofactors. Post-transplant lymphoproliferative disorder (PTLD) is the most common malignancy in pediatric transplant recipients followed by skin cancer and a large group of less common solid tumors. Through the use of short presentations, panel discussion, and case presentations this workshop will provide participants with a working knowledge of the biology, risk factors, presentation and management options for PTLD, and other malignancies following transplant. Emerging data from the transplant tumor registries, open treatment protocols, and controversies in patient management will be shared and discussed.