We report the PET-CT appearance of extraosseous myxoid chondrosarcoma in the left gluteus maximus muscle with diffuse pulmonary and nodal metastases in a 65-year-old man who presented with a large left gluteal mass. Pretherapeutic tumor SUV obtained by FDG PET imaging has been reported as a useful parameter for tumor grading and prediction of outcome in chondrosarcoma patients. In addition, the combination of SUV and histopathologic tumor grade further improves prediction of outcome substantially, allowing identification of patients at high risk for local relapse or metastatic disease.