Skeletal and soft tissue sarcomas need early and accurate diagnosis, staging, and treatment for optimal outcome. 18F-FDG PET/computed tomography (CT) is indicated in staging of patients with high-grade sarcomas and acts as a surrogate marker of histopathologic grade, guiding biopsy to most aggressive portion of the tumor. Pretherapy and posttherapy 18F-FDG PET/CT metabolic parameters are reliable indicators of survival in patients with sarcoma with an important role in posttreatment response assessment, enabling the treatment plan to be modified in nonresponders. 18F-FDG PET/CT is particularly useful in the evaluation of molecular targeted therapies, which induce metabolic change before structural change.