Little is known about the clinical value of FDG PET for assessing treatment response in pediatric oncology. After systematic review of literature, the very few publications concerning response control in pediatric oncology using FDG PET are summarized. There were only 4 studies concerning FDG PET in the assessment of therapy response in pediatric patients. None of the publications fulfilled the requirements for high quality studies because of the small number of patients studied. The clinical value of FDG PET in the assessment of therapy response in pediatric oncology is likely in osseous sarcomas and possibly in high-grade brain tumors. In other pediatric tumor entities such as lymphomas, soft-tissue sarcomas, germ cell tumors, or neuroblastomas, the clinical usefulness of FDG PET can either be assumed analogous to adults, or can be assumed from staging studies, or is still unknown. There is a need for large, systematic studies evaluating FDG PET in therapy monitoring, but also in grading, staging, and in the diagnosis of recurrences in pediatric malignancies.