Posttransplantation lymphoproliferative disorder (PTLD) is a histologic heterogeneous disease that complicates 4 to 8% of lung transplant recipients. Disease extent is an important prognostic factor and may affect therapy. Positron emission tomography with fluoro-2-deoxy-D-glucose (FDG-PET) has proven useful for staging high-grade lymphomas but is less accurate for staging low-grade and extranodal lymphoma. This study examined our initial experience using FDG-PET imaging to stage lung transplant recipients with posttransplantation lymphoproliferative disorder. FDG can show foci of uptake, particularly in extrathoracic sites, not seen by conventional imaging, which allows more accurate staging of disease thereby yielding useful prognostic information and guiding therapy.