Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) are among the most common malignancies of childhood. (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) can be employed for accurate staging, treatment planning, and response assessment in pediatric patients with lymphomas, taking advantage of the increased FDG uptake of the malignant cells, secondary to their increased metabolic needs. FDG PET has higher sensitivity than other imaging modalities to detect nodular or diffuse lesions and higher sensitivity than bone marrow biopsy to detect bone marrow infiltration. FDG PET consists of an invaluable imaging modality during evaluation and treatment of pediatric lymphomas.